Momentum Vector

Introduction:

Measurement of motion of a body can be explained by momentum vector.

Definition of momentum vector:

Momentum vector is defined as the total motion contained in the body. Mathematically, momentum vector is equal to the product of mass of the body and its velocity.
P = m × v
Where m is the mass of the body and v be the velocity of the body.
Momentum vector is a vector quantity. The unit of momentum vector is kg m /s in MKS and g cm /s in CGS.

Principle of Conservation of Momentum Vector:

It states that if no external force is applied on a system, then the momentum of the system remains constant. In other words, if there is no external force applied on the system,
the initial momentum of the system will be equal to the final momentum of the system Consider a system of two bodies on which there is no external force acting on it. Because the system is isolated from the surroundings, so it interacts only due to their mutual interactions. Due to the mutual interaction, the momentum of the individual bodies may change but the total momentum of the system remains constant. If q₁ and q₂ be their individual momentum's, then
q₁ + q₂ = constant
For a system of n bodies, we can say that, q₁ + q₂ + q₃ +…..+ q_n = constant

Practical Application of Principle of Conservation of Momentum Vector:

When a bullet is fired from the gun, the gun recoils or gives a jerk in the shoulder in the backward direction. Let M be the mass of gun and m be the mass of the bullet. Initially both bullet and the gun are at rest. On firing the gun, suppose that the bullet moves with velocity v and the gun moves with velocity V. As we use the principle of conservation of momentum,
Total momentum of the gun and the bullet before firing = total momentum of the
         bullet and the gun after firing
0 = MV + mv
V = - mv / M
The negative sign shows that the gun will move in the opposite direction of bullet.

Angular Momentum for Rigid Body

Introduction:

The angular momentum definition of a particle is defined as the moment of linear momentum of the particle.
Let us consider a system of n particles of masses m₁,m₂,m₃..............m_n situated at distances of r₁,r₂,r₃,.......,r_n respectively from the axis of rotation .

Let v₁,v₂,v₃, ....be the linear velocities of the particles respectively, then the linear momentum of the first particle = m₁v₁

Definition of Angular Momentum for Rigid Body:

Since v₁ = r₁`omega`
Linear momentum of the first particle =m₁(r₁`omega` )
The moment of linear momentum of first particle = (m₁r₁`omega` )x r₁
Angular momentum of first particle = m₁r₁²`omega`
Similarly angular momentum of the second particle = m₂r₂²`omega`
and angular momentum of the third particle = m₃r₃²`omega` and so on.
The sum of moment of the linear momenta of all the particles of a rotating rigid body taken together about the axis of rotation is known as angular momentum of a rigid body.

Calculating the Angular Momentum for Rigid Body:

`:.` Angular momentum if the rotating rigid body = sum of the angular momenta of all the particles
`rArr` L = m₁r₁²`omega` +m₂r₂²`omega` +m₃r₃²`omega` +.............+m_nr_n²`omega`
`rArr` L = `omega` [ m₁r₁² +m₂r₂²+m₃r₃²+.....+m_nr_n²]
         =`omega[ sum_(i=1)^n m_i r_i^2]`
`rArr` L = `omega` I
where I = `sum_(i=1)^n m_ir_i^2` = moment of inertia of the rotating rigid body about the axis of rotation.

Problem to find the angular momentum of a cylinder:
A solid cylinder of mass 200kg rotates about its axis with angular speed 100 s^-1  .The radius of the cylinder is 0.25m.What is the magnitude of the angular momentum of the cylinder about its axis?
Given data : Mass M = 200 kgs
Angular speed `omega` =100 s^-1
Radius R=0.25m
L= ?
Formulas : I = `(MR^2)/2`
L = I`omega`
Working: I = `(MR^2)/2= (200 xx (0.25)^2)/2 = 6.25 "kg" m^2`
L = I`omega` = 6.25 x 100 = 625 Kg m² s^-1

Check my best blog Atomic Number of Curium.

Atomic Number of Curium

Curium is a silvery metal that is hard and brittle and tarnishes gradually in air at room temperature.

Introduction to atomic number of curium

It is first produced by Glenn T. Seaborg, Albert Ghiorso, and Ralph A. James at University of California in 1944. Its symbol is Cm and the atomic number of curium is 96. Curium does not occur in nature and is a synthetic chemical (produced artificially) produced in nuclear reactors by bombarding plutonium with helium ions (alpha particles).

Properties of Curium

• Molecular Weight: 247.070347 [g/mol]
• IUPAC Name: curium
• Canonical SMILES: [Cm]
• InChI: InChI=1S/Cm
• InChIKey: NIWWFAAXEMMFMS-UHFFFAOYSA-N
• Atomic number of curium: 96
• Element category: actinide
• Period and block: 7, f
• Electron configuration: [Rn]7s25f76d1
• Phase: solid
• Density: 13.51 g•cm−3
• Melting point: 1613 K
• Boiling point: 3383 K
• Crystal structure: hexagonal close-packed
• Atomic Radius: 170 pm
• Oxidation States: 3

Uses of Curium

• Curium is available only in extremely small quantities. Curium can be used as source of thermoelectric power in crewless space probes and satellites without any heavy shielding.
• Curium-242 isotope is used in radio isotopic power generators as it produces around 3 watts of heat energy per gram (through radioactive decay).
• Curium-242 is used as source of alpha particles in lunar missions to bombard alpha particles to the moon’s soil to determine materials present in moon soil.

Isotopes of Curium

About sixteen different isotopes of curium are present and some of the main isotopes are Cm-242, with half life of 160 days, Cm-243, with half life of 29 yr, Cm-244, with half life of 18 yr, Cm-245, with half life of 8,500 yr, Cm-246, with half life of 4,700 yr, Cm-247, with half life of 16 million yr, Pu-243, with half life of 5.0 hr, Cm-248, with half life of 340,000 yr, Cm-250, with half life of 6,900 yr, Pu-246, with half life of 11 days, Bk-250, with half life of 3.2 hr, and Am-246, with half life of 39 min.

The Chemical Formula for Aluminum

Aluminum belongs to group 13 of the periodic table. It was first discovered by Wohler in 1827. It is the third most abundant element in the earths crust. The atomic number of aluminum is 13. Aluminum forms a tri-positive ion i.e. Al3+. It is less electropositive than sodium and magnesium.

PROPERTIES OF ALUMINIUM

PHYSICAL PROPERTIES

1) Aluminum is a soft silvery white metal. The fresh metal on exposure to moist air loses its shining due to formation of oxide layer on its surface.

2) It is very light metal with specific gravity equal to 2.70.
Chemical Properties of Aluminium

(1) Action of air.

(a) Aluminum is not affected by dry air but in moist air a thin film of oxide is formed on its surface.

(b) It burns with oxygen with a brilliant white light with the evolution of heat

4Al +3O2 ----> 2Al2O3

(2) Action of water: Aluminum is not affected by pure cold water. However, saline water corrodes rapidly especially when it is hot. It decomposes boiling water. In the form of amalgam, it reacts more easily and rapidly with water and can decompose it even in cold.

2Al + H2O ----> 2Al (OH) 3+ 3H2

(3)Action of acids: Aluminum dissolves in dilute hydrochloric acid forming aluminum chloride with the evolution of di-hydrogen gas.

2Al + 6HCl  ----> 2AlCl3 + 3H2

Aluminum is not attacked easily by dilute sulphuric acid. This probably is due to insolubility of oxide layer (present on its surface) in the acid. However, it dissolves in hot and concentrated sulphuric acid to form sulphur dioxide.

2Al + 6H2SO4 ----> Al2 (SO)3 + 2SO2 + 6H2O
Uses of Aluminium

1)     Auminium is used for making electrical transmission cables.

2)     Aluminium powder is used as a reducing agent inj Goldschmidt aluminothermic process and thermite welding.

3)     It is used in making household utensils and novelty articles.

4)    Aluminium foil is used for wrapping soaps, cigarettes, confectionary, etc.

5)     It is used for making silvery paints for covering iron and other materials.

6)     It is used as dexidiser for removing blow holes in metallurgy.

7)     Due to low density, good thermal and electrical conductivity and resistance to corrosion, aluminium is used for making several alloys which are extensively used in automobile and automobile industries.

Chemical Reactions

The process of transformation of chemical substance to another is known as chemical reaction.

A chemical change involves the formation and cleavage of chemical bonds between atoms. Any chemical change can be described by using a chemical equation which gives complete idea about conversion of molecules during reaction.

Let’s elaborate; what is a Chemical reaction. It can define as change in bonding of reacting molecule to form new chemical compound by the formation of new chemical bonds.

The chemical substances take part in chemical reactions is called as reactant and newly formed substances are known as products. A chemical change can complete in one step or multi steps which can be described by using reaction mechanism. Chemical equation is the graphical representation of such a reaction which provides direction of reaction, physical states of reactant and products and the number of molecules taken part in reaction.

Different Types of Chemical Reactions and examples are as follow;

1. Combustion: Oxygen combines with substance to form carbon dioxide and water with a large amount of heat.

CH₄+ 2 O₂  CO₂ + 2H₂O

2. Synthesis: two or more chemical substance combines to form a more complicated one.

2Mg + O₂ 2MgO

3. Decomposition: A complex molecule decomposes in to simpler ones.

2HI  H₂ + I₂

4. Single displacement: one element trades places with another element in a compound.

Mg + 2 HClMgCl₂ + H₂

5. Double displacement: The anions and cations of two different molecules interchange and form two entirely different compounds.

BaCl₂ + H₂SO₄  BaSO₄ + 2HCl

6. Neutralization: A double displacement reaction between acid and base to form salt and water.

HCl + NaOH  NaCl + H₂O

There are a many observations which indicate a chemical change has occurred. These are called as Signs of a Chemical changes. Like; the formation of a precipitate during chemical reaction is one the best sign which can observe easily. When an ionic compound reacts with other to form insoluble salt, it gets settle down at the bottom of test tube in the form of precipitate. Other signs of chemical-reactions are;

• Color change.
• Liberation or absorption of energy.
• Formation of gas.
• Change in temperature of reacting solution

Let’s perform any Chemical Reaction Experiments and observe sign of reaction.

Take 1-2 ml of a 0.1 M lead (II) nitrate solution in a test tube and add it to 1-2 ml of a 0.1 M potassium iodide solution. When lead nitrate reacts with potassium iodide it form yellow colour precipitate of lead iodide it’s an example of double displacement reaction.

Pb(NO₃)₂ + 2KI  PbI₂ + 2KNO₃

Hence color change and precipitate from colorless reactants can be observed in reaction.

Moment of Inertia Sphere

The moment of inertia of a point mass about a known axis is defined by I = mr²  where m is its mass and r is its perpendicular distance from the axis of rotation.

Introduction :

Definition :  The moment of inertia of a rigid body about an axis is defined as the sum of the products of the masses of different particles, supposed to be constituting the body, and the square of their respective perpendicular distances from the axis of rotation.
                     Moment of inertia of a sphere can be explained in two parts (1) Solid Sphere (2)Hollow Sphere.
(1) Moment of inertia of a Solid Sphere  :  
    (a) About an axis passing through its diameter :   Consider a solid sphere of mass M and radius R. Its moment of inertia about an axis of rotation passing through its diameter is
                                                                            I  =  MR²
   (b) About an axis passing through its tangent  :   Let A'B' the tangent to the solid sphere. A parallel axis through its centre of mass is AB

By parallel axes theorem,
 Moment of inertia about the tangent = Moment of inertia about a diameter + Mr² .
                                                                  =`(2)/(5)` MR² + MR²
                                                         I      =  `(7)/(5)` MR² .

Moment of Inertia Sphere : Hollow Sphere

(2) Moment of Inertia of a Hollow Sphere
(a) Moment of inertia about an axis passing through the diameter of a hollow sphere of mass M and radius R is
                                                I  =`(2)/(3)`   MR² . 
(b)  Moment of inertia about an axis passing through its tangent can be obtained by applying parallel axes theorem. It is given by
                                                  I  =  `(5)/(3)` MR² .

Moment of Inertia Sphere : Example Problem

Problem : If the radius of the earth is suddenly halved keeping its mass constant, find its time period of rotation around its own axis.
Solution :  When the radius of the earth gets reduced suddenly keeping its mass constant, the angular momentum of the earth remains constant.      
                                                I   = constant
     If I changes from I₁ to I₂ ,   changes from`omega` ₁  to`omega`  ₂ so that 
                                          I₁ `omega`₁  =  I₂`omega`₂ .
     Assuming the earth to be a solid sphere, its moment of inertia about its diameter,
                      I  =  MR²
   If the radius changes form R to R/n
                                           `(2)/(5)` MR₁² `omega`₁  =  `(2)/(5)` MR₂² `omega`₂ 
                                                           R²  =  `(2pi)/(24 hours)`  = [R / n]² `(2pi)/(T)`  
          The time period of rotation , T = 24 hours / n² .
      In this problem, the radius changes from  R  to R / 2 .
                         `:.`   `(2)/(5)` MR²  `(2pi)/(24 hours)`   =  `(2)/(5)` M [R/2]² `(2pi)/(T)`
                               T  =  24 / 2²   =  24 / 4  =  6 hours.

Alkaline Metal facts

Introduction :

Alkaline metals are of very keen importance to us. These metals were discovered in the first decade of 19th century by an English chemist Sir Humphry Davy (1778- 829). Along the same time, he also found some elements of other metal families. Alkaline metal facts include all the basic properties shown by them.

About Alkaline Metals
Alkaline metals constituting Group2 of the Periodic Table. These metals show some general properties which are as follows:

• These metals are softer than most other metals
• These metals readily react with water (especially when heated).
• These metals are powerful reducing agents.
• These metals form divalent compounds, etc.

Facts Related to Alkaline Earth Metals

There are various facts related to Alkaline earth metals, some of the important ones are as follows:

• The name alkaline metals owes to their oxides that simply give basic alkaline solutions. These metals melt at high temperature and remain solids in heated atmospheres.
• The alkaline metals show good trend in their properties in the periodic table, with well-defined homologous behavior in going down the group.
• Some alkaline metals like Be and Mg, they show a distinguishable flame color , brick-red for Ca (Calcium) , Magenta-Red for Sr (Strontium) , Green for Ba (Barium) and crimson red for Ra (radium).
• The metals coming in this group show patterns in their electronic configuration, especially the behavior of them in their outermost shells, which results in the trend in chemical behavior.
• The alkaline metals are mostly Silver colored, soft metals, which react readily reactions with halogens.
• Alkaline Metal like Beryllium is highly toxic, it is rarely available to biological systems, and it has no known role in living organisms.
• Other Alkaline metal like Magnesium and calcium are essential to all known living things. They are involved in many roles like in some cellular processes, Mg functions as the active centre of the enzymes and Ca salts takes structural roles.
• Strontium and barium have lower availably in the atmosphere. They play very important roles in marine aquatic life, especially hard corals. These two are also used in medicines. Strontium is used to build the exoskeleton.
• The last metal that is Radium has a low availability and is very highly radioactive.

Conclusion

Alkaline earth metals are of very keen importance to us. These metals are highly important for the automobile industries due to their structure qualities. These metals are of great concern, as they are also included in building machines and other important equipment. 

Nomenclature and Structure of Carboxyl Group

Introduction :

In aldehydes the carbonyl compilation is connection to a carbon and hydrogen as in the ketons is attachment to carbon atoms. The carbonyl combine in to carbonyl acids derived as in combine where carbon is attachment to nitrogen with to halogens are identified amides along with acyl correspondingly. The frequent method of these module combine as aldehyde, ketone.

Nomenclature and Structure of Carboxyl Group Carboxylic Acids:

Aldehydes with ketones as well carboxylic acids are huge increase in plant life along with animal empire. They cooperate an important position in biochemical technique of existence. They append smell by flavour to environment.Carbon compound comprise a carboxyl well-organized locate –COOH are identified carboxylic acids. The carboxyl grouping, consists of a carbonyl grouping append to a hydroxyl group, thus the surname carboxyl. 

Nomenclature and structure Carboxylic acids capacity be aliphatic depending list the collection, alkyl or aryl append toward carboxylic carbon. huge digit of carboxylic acids are ascertain in environment. a number of advanced correlate of aliphatic carboxylic acids identified as greasy acids, happen in usual heavy since ester of glycerol.  Carboxylic acids afford as initial substance for a number of supplementary significant organic complex such similar to anhydrides.
They are develop  in amny foodstuff yield also pharmaceuticals toward include flavours. a number of these people are influence for utilize since solvents to is acetone with for categorize equipment similar to adhesives.

Nomenclature and structure of carboxyl group:
Carboxylic acids are amongst the initial organic compounds to subsist isolated from environment a huge quantity of them are accepted by their frequent names.
The normal given name end with the suffix –ic acid also have derived from latin names of their accepted foundation. intended for naming compounds containing supplementary than one carboxyl group, the finale –e of the alkane is retained.
Structure of carboxyl group:
Nomenclature and structure carboxylic acids the acquaintance to the carboxyl carbon be located in one plane as well as are separated by concerning 120°. The carboxylic carbon is with a reduction of electrophilic than carbonyl carbon as of the feasible resonance structure.

Definition of some Important Terms Pertaining to Coordination Compounds

Introduction:
Complex ion, exciting molecular collective consisting of a metallic atom or ion to which is emotionally involved single or additional electron-donating molecules. In a number of complex ions, such as sulfate, the atoms are so tightly bound collectively that they do something as an only unit. A lot of complex ions however are simply loosely aggregated and lean to distance in a water solution until equilibrium is recognized connecting the complex ion and its important components.

Some Important Terms Pertaining to Coordination Compounds:

Definition of Central atom/ion compounds:

In terms pertaining of coordination entity is definition; the atom/ion to which a fixed number of ions/group is bound in a definite geometrical arrangement around is called the central atoms or ions.
Ligands compounds:
The terms pertaining ions or molecules bound to the central atoms ion in the coordination entity are called ligands. These may be simple ions such as Cl-, Small molecules such as H2o or NH3, larger molecules such as H2NCH2CH2NH2 or N (CH2CH2NH3) or even macromolecules such as proteins.
Definition of coordination number:
Some terms pertaining of synchronization numeral of a metal ion in a complex can be distinct as the number of ligands donor atoms to which the metal is straight bonded.
Definition of coordination sphere:
The central atom/ions and ligands attached to it are enclosed in square, bracket and are collectively terms pertaining as the coordination sphere. Some ionization groups are written outside the bracket and are called counter ions.
Definition of coordination polyhedron:
The spatial arrangements of the important ligand atoms which are directly attached to the central atoms/ion definition terms a coordination polyhedron about the central atoms.
Definition of oxidation number of central atoms compounds:
The oxidation number of the central atom in a some complex is definition as the charge it would carry if all the ligands are removed along with the electron pair that are shared with the central atoms.

Homoleptic and Heteroleptic Complexes Compounds:

         Important complex in which a metal is bound to only one kind of donor group [CO (NH3)6)3+ are known as homoleptic. Important Complex in which a metal is bound to more than one kind of donor group are known as hetroleptic.

Properties of Transverse Waves

Introduction 

A transverse wave is a type of mechanical wave. They travel in a straight line and carry energy and momentum through medium particles from one point to another.
“If on propagation of a mechanical wave through a medium, the medium particles oscillate along a direction perpendicular to the direction of propagation of the wave, the wave is called a transverse wave.”  In other words, if wave travels in x- direction, medium particles vibrate up or down or along y- direction. For example, when one end of a horizontal rope is tied to a hook and the other end is moved up and down, a transverse wave travel horizontally while particles of rope vibrate up and down.
There are several examples of transverse waves in everyday life.               
Vibrations in string, surface water waves, electromagnetic waves, seismic S (secondary) waves, audience wave.

Properties of Transverse Waves

A transverse wave has all properties of mechanical waves.

1. Amplitude- The maximum vertical displacement of the medium particles on either side of its equilibrium position is called the amplitude. It is denoted by ‘a’.
2. Time period- The time taken by medium particle in completing one oscillation is called as the time period of wave.it is denoted by ‘T’.
3. Frequency- The number of oscillations made by a medium particle in 1 second is called as frequency of wave. It is denoted by ‘f’.
4. Phase- The phase of the wave at any instant denotes the position and direction of motion of medium particle at that instant.
5. Wavelength- The distance travelled by the wave in one complete oscillation

is called as wavelength of wave. It is denoted by ‘λ’.

Properties of Transverse Waves : Speed

Wave speed- The distance travelled by the wave in one second is called as ‘wave speed’. It is denoted by ‘v’.
Transverse waves can be formed only in solids because solids have rigidity.
(i)                Speed of transverse wave is given by the following formula-
                              V =√ (η / d)
Where, η is modulus of rigidity of material and d is the density.
(ii)              Speed of transverse waves in flexible stretched string is given by following formula-
                              V = √ (T / m)
 Where T is the tension in the string and m is the mass per unit length of string.

Longitudinal Waves Compression

Introduction:      

When a stone is dropped into water in a pond. waves are produced at the point where the stone strikes and water. The waves (ripples) travel outward and particles of the water vibrate up and down about their mean positions. This can be clearly seen when the leaves floating on the surface of the pond move up and down as the ripples pass on. They do not travel along the wave. Similarly, when a tuning fork is set into vibrations, waves are produced in the surrounding air making the particles of the air oscillate about their mean positions. Hence a wave motion can be defined as a form of disturbance which travels through the medium due to repeated periodic motion of the particles of the medium about their mean positions, the disturbance being handed over from one particle to the next. in the process the energy and momentum of the particles is successively transmitted through the medium in the wave form known as a progressive wave or a travelling wave. Such a wave travels with a constant speed in the medium.

Longitudinal Waves Compression

The direction of propagation of waves relative to the direction of vibration of the particles of the medium classifies them into two types, namely  longitudinal waves and transverse waves.

Longitudinal waves :
 If the particles of the medium vibrate parallel to the direction of propagation of the waves, the waves are called 'Longitudinal waves'. The propagation of longitudinal waves can be demonstrated as shown in the figure below. 

Longitudinal Waves Compression : Simulation

Let a light spring held horizontally be given a push in the same direction. The spring gets compressed sending a pulse of pressure along the spring. Soon this compression tends to release the pressure in the region by pushing the neighbouring (particles) layers of the spring. This is known as rarefaction. Thus the compressions transmitted horizontally along the length of the spring .If the pushing at the end of the spring is repeated at regular intervals of time a periodic longitudinal progressive wave takes place along the length of the spring.
Sound waves are longitudinal waves. Longitudinal waves can travel in solids, liquids and in gases as well.

Electromagnetic Spectrum Animation

Introduction:

The waves do not require medium for their propagation are called electromagnetic waves. These waves propagate in vacuum with speed of light c=3`xx` 10^-7m/s and on account of being chargeless they are not deflected by electric and magnetic fields. These electromagnetic spectrum is done in an animation.

Newton obtained the spectrum of sun and observed that all colours from red to violet exist continuously in the sun’s spectrum. The wavelength of violet colour is 4.0`xx` 10^-7m and the wavelength of red colour is 7.8`xx`10^-7m.

Electromagnetic Spectrum Animation

Visible spectrum in electromagnetic spectrum animation:

The region of spectrum from the wavelength 4.0`xx` 10^-7m to 7.8`xx`10^-7m is called visible spectrum, because all colours between this wavelength range are visible.

Infrared spectrum in electromagnetic animation:
The region of spectrum below violet is called ultraviolet spectrum while that above red is called infrared spectrum. The ultraviolet and infrared radiations are invisible.

According to the wavelength range, the whole electromagnetic spectrum animation is divided from very short gamma rays to long radiowaves.

Properties:
Electromagnetic spectrum animation properties:
Gamma rays ( - rays):

• They lie in the upper frequency range of electromagnetic spectrum.
• Their wavelength range from 10^-13m to 10^-10m.

 Discoverer: Becquerel in 1986.
 Origin: They are produced in nuclear reactions and emitted by disintegration of atomic-nuclei.
Properties: Chemical reaction on photographic plates, fluorescence, phosphorescence, less ionizing but high penetrating power.
 X-rays:

• Wavelength range from 10^-10 m to 10^-8.

Discover: Roentgen in 1896.
Origin: They are emitted due to bombardment of high energetic electrons on heavy target
Properties: All properties of  - rays but less penetrating and more ionizing power.

Ultraviolet Radiation:

• Wavelength range from 10^-8 m to 4.0`xx` 10^-7m.

Discover: Ritter in 1801.
Origin: They are emitted due to bombardment of high energetic electrons on heavy target.
Properties: Less penetration and produce photoelectric effect. Fortunately most of ultraviolet rays are absorbed by ozone layer of atmosphere.
Visible Light:

• Wavelength range from 4.0`xx` 10^-7m to 7.8`xx`10^-7m.

Discover: Newton in 1666.
Origin: Produced by incandescent bodies and ionized gases.
Properties: Produce photoelectric effect and sensation of vision.
Infrared Radiation:

• Wavelength range from 7.8`xx`10^-7m to 10^-3_.

Discover: Hershell in 1800.
Origin: Produced by hot bodies.
Properties: Prodominant heating effect, night photography.
Hertzian Waves:

• Wavelength range from 10^-3m to 1m.

Origin: By spark discharge.
Discover: Hertz in 1888.
Properties: Produce sparks in gaps of receiving circuits. The waves of wavelength range from 1mm to 3cm are also called microwaves.

I like to share this Electromagnetic Spectrum Radio Waves with you all through my article.

Long  Radio Waves:

• Wavelength range from 1m to 10⁵m. The frequency range of radio wave is 0.5MHz to 1000MHz.

Discover: Marconi in 1895.
Origin: These waves are generated by accelerated motion of charges in conducting waves or oscillating circuits.
Properties: Reflected  by layers of atmosphere.

Check my best blog Halogen Family Characteristics.

Halogen Family Characteristics

Introduction:
Halogens are the group of elements present in the seventeenth group of the Periodic Table. This group is also numbered as 7A group. The elements in order are: -

S.No.	NAME	ATOMIC NUMBER	ATOMIC MASS (amu)
1.	Fluorine (Fl)	9	19
2.	Chlorine (Cl)	17	35.5
3.	Bromine (Br)	35	79.9
4.	Iodine (I)	53	126.9
5.	Astatine (At)	85	210

Halogen Family Characteristics:

The halogens are non-metals. They are electronegative elements, since they tend to gain electrons to form negatively charged ions.
They have the highest values of electro-negativity in their respective periods. Fluorine and Chlorine are gases in state,  Bromine is a liquid, and Iodine and Astatine are solids. Astatine is a very unstable element, and it is found rarely in nature.
The Halogens are all strong oxidising agents since they accept electrons to form compounds. They readily and directly combine with electro-positive elements (metals) to form ionic compounds owing to their strong affinity for electrons. Their last shell or the valence shell, contains seven electrons, and in order to complete its octet they need to gain one electron for each atom. This also causes the Halogens to be one of the most highly reactive elements. Examples of compounds formed between Halogens and metals: -

• Common salt (NaCl) : Reaction Na + Cl → NaCl
• Lithium Fluoride (LiF): Reaction 2Li + F₂ → 2LiF
• Potassium Bromide (KBr): Reaction 2K + Br₂ → 2KBr

Halogens also form covalent compounds:-

• Hydrochloric acid (HCl): Reaction H₂ + Cl₂ → 2HCl.

The color of Halogens varies from top to bottom in the group, the top element Fluorine is the lightest colored, being light yellow, and the lowest element Astatine is the darkest, being black in color.

Amplitude Modulation Transmitter

Introduction :

Block diagram of AM transmitter is shown below.

Parts of am Transmitter:

Master Oscillator:-
The master oscillator generates a stable sub harmonic carrier frequency (i.e. the fraction of a desired carrier frequency). This stable sub-harmonic oscillation is generated by using a crystal oscillator and then frequency is raised to the desired value by harmonic generator. The carrier frequency ought to be very stable. Any change in the master oscillator frequency will cause interference with other transmitting stations and receiver will accept programmes from more than one transmitter.
Buffer Amplifier:-
This is a tuned amplifier providing high input impedance at the master oscillator frequency. Any variation in load current does not affect the master oscillator due to this high input impedance of buffer amplifier at the operating frequency of the master oscillator. Thus, buffer amplifier isolates the MO from the succeeding stages, so that the loading effect may not change the frequency of the master oscillator.
Harmonic Generator:-
It is an electronic circuit that generates harmonics of its input frequency. The principle of harmonic generation is the same as that of a non-linear modulator. When a signal is applied to a non-linear circuit, it generates harmonics of input frequency. The desired harmonic is selected by a properly tuned circuit. The circuit uses a class C tuned amplifier.

Parts of am Transmitter:

Driver Amplifier or Intermediate Power Amplifier:-
One or more stages of a class C tuned amplifier are used to increase the power level of a carrier signal to provide a large drive to the modulated class C amplifier. The output of the harmonic generator provides a low power carrier signal. This power is amplified to raise power to desired level to drive the final amplifier stage. This stage is termed as driver amplifier or intermediate power amplifier.
Modulation system:-
The collector modulation circuit is used for modulation in high power transmitters. The modulating amplifier is a class A, or class B amplifier amplifying the base band signal.
Feeder and Antenna:-
The transmitter power is fed to a transmitting antenna for effective radiation. The length of the antenna (a conductor) should be of the order of the wavelength for effective radiation. The antenna is normally located at a distance from the transmitter and hence power from the transmitter is fed to the antenna through a properly designed transmission line called feeder.

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Check my best blog Extraction of organic compounds.

Extraction of organic compounds

Introduction :

The process of removing a substance from its aqueous solution by shaking with a suitable organic solvent is termed as Extraction. If the organic compounds are removed from aqueous solution, this process is called as Extraction of organic compounds.

Extraction of Organic Compounds with a Solvent

When an organic substance is present as solution in water, it can be recovered from the solution by the following steps:

1. The aqueous solution is shaken with an immiscible organic solvent in which solute is more soluble
2. The solvent layer is separated by means of a separating funnel.
3. The organic substance is then recovered from it by distilling off the solvent.

Procedure: The aqueous solution is placed in a separating funnel. A small quantity of the organic solvent, say ether or chloroform, is then added to it. The organic solvent being immiscible with water will form a separate layer. The mouth of the funnel is closed with a stopper or palm of the hand and shaken gently. The solute being more soluble in the organic solvent transferred to it. The solvent layer is then separated by opening the tap and running out the lower layer. The organic substance dissolved in it is finally recovered by distilling off the solvent. It is always better to extract 2 or 3 times with smaller quantities of the solvent than once with the bulk of the solvent provided.

Extraction of Organic Compounds with Soxhlet

When an organic substance is to be recovered from a solid, it is extracted by means of an organic solvent in which the impurities are insoluble. In actual practice the extraction from solids is often tedious and requires thorough contact and heating with the solvent. This is done on special apparatus. The soxhlet extractor.
Procedure: the powdered material is placed into the thimble made of stout filter paper. The flask containing a suitable solvent is heated on a water bath or sand bath. As the solvent boils, its vapors rise through the side tube up into the water condenser. The condensed liquid drop on the solid in the thimble dissolves the organic substances and filters out. As the level of liquid rises, the solution flows back into the boiling flask. The solvent is once again vaporized, leaving behind the extracted substance in the flask. In this way a continuous stream of pure solvent drops on the solid material, extracts the soluble substances and returns to the flask. At the end of the operation the solvent in the boiling flask is distilled off, leaving the organic substance behind.

Properties of Ionic Compounds

Introduction:

A chemical compound in which ions are held together in a lattice structure by ionic bonds is called Ionic compounds. Normally, the positively charged portion have metal cations and the negatively charged portion is an anion or polyatomic ion.

Ions can be single atoms, or more complex groups. But an ion must have a positive or negative charge. So, in an ionic bond, one must exhibit a positive charge and the other negative one.

Chemical compounds are not strictly ionic. The most electronegative/electropositive pairs like caesium fluoride have a degree of covalency. Similarly, covalent compounds have charge separations.

Characteristics of Ionic Compounds

All atoms are electrically neutral. This is because all atoms have the same number of electrons and protons. Each electron has a negative charge of  -1 unit and each proton has a positive charge of +1 unit. Thus, the negative charge of electrons is canceled by positive charge of protons. This is the normal state of the atoms of any element.
Except for the atoms of noble gases, all elements' atoms are not stable. Here, "stable" implies a complete octet or a duplet structure. In an octet or duplet, the last shell or orbit of an atom possesses either 8 or 2 electrons respectively. When an atoms shows octet or duplet structure, it is assumed to be completely stable, and it does not take part in chemical reactions and hence, does not form compounds. All noble gases have octet or duplet electronic configuration.
Therefore the elements' atoms, except noble gases, always attempt to attain an octet or a duplet. In order to do so, they either lose, gain or share electrons. When an atom has lesser than 4 electrons in its valence shell, it tends to lose these valence electrons so as to become stable. When an atom has more than 4 electrons in its valence shell, it tends to gain 3, 2 or 1 electrons to attain stability.
Generally, metals (alkali metals and alkaline earth metals) tend to lose electrons, and nonmetals (group 17 elements mainly) tend to gain these electrons. Thus, metal atoms become positively charged ions and non metal atoms become negatively charged ions, and as unlike charges attract each other, so these ions get attracted by strong electrostatic forces and form a compound called an ionic compound, whose chemical bond is called an ionic or electrovalent chemical bond.

Ionic compounds have strong electrostatic bonds present between particles. They normally have very high melting and boiling points. They exhibit good electrical conductivity when present in molten or in aqueous solution. As ionic inorganic compounds are solids at room temperature and form crystals.

Solubility

Following the phrase, "like dissolves like", ionic compounds easily dissolve in polar solvents, and those which ionize with water and ionic liquids. They are appreciably soluble in other polar solvents like alcohols, acetone and di-methyl sulfoxide. Ionic compounds do not tend to dissolve in nonpolar solvents like diethyl ether or petrol.

The oppositely charged ions in the solid ionic lattice are surrounded by opposite pole of the polar molecule which try to pull them out of the lattice to the liquid. When the force applied is more than the electrostatic attraction of the lattice, the ions gets into the liquid and dissolves in it.

Electricity Conductivity

Solid ionic compounds are mot able to conduct electricity as there are no mobile ions or electrons present in the lattice. When the ionic compunds are dissolved in a liquid or molten form, they can conduct electricity with the mobile ions.

Physical state:-

Ionic compounds exist in the form of crystalline solids (at room temperature).

This is because their constituent particles are ions, and the strong attractive forces between the oppositely charged ions hold them closer and lock them in fixed positions in the crystal structure of the solid.

Lattice structure:-

The lattice of a substance can be considered as the structure of its crystal which is visible under a microscope.
The constituent particles being oppositely charges ions, the electrostatic forces between the oppositely charged ions cause the ions to be arranged closely, in a geometric patter in the lattice. For example, in Sodium Chloride (NaCl), the ions are arranged in a cubic lattice such that each sodium ion is surrounded by 6 chlorine ions and each chlorine ion is surrounded by six sodium ions. Thus, ionic compounds do not show a molecular arrangement.

Let us look at the reasons why ionic compounds have high melting points:

The melting points of ionic compounds are usually high. Crystals are formed by almost all ionic compounds. Salts readily form crystals by forming stacking groups with the small amounts of electrical negative and positive charges. The crystals thus formed are very big molecules with large amounts of positive and negative charges that are stuck together. A massive amount of energy is required for breaking the opposite charged ions apart. This breaking apart of the oppositely charged ions requires additional energy, which is supplied when the compound is heated. At increased temperatures, the energy supplied to the compound is more for breaking it up forming oppositely charged positive and negative ions, which further melts. Hence, during laboratory experiments, the melting of ionic compounds may not achieved by heating on a Bunsen burner, since the melting points of these ionic compounds are very high.
Ionic compounds due to the high electro negativity have high melting points and the strong intermolecular forces between results in an increase in the melting points of ionic compounds. The ionic bonding between the oppositely charged negative and positive ions involved in the formation of an ionic compound is very strong, which makes the compound very stable and hence requires high temperatures for the bonds to break apart and further melting of the ionic compound.

Examples of Ionic Compounds:

Table salt NaCl,

Zinc chloride ZnCl,

Copper Floride CuF₂,

Sodium hydroxide NaOH,

Potassium hydroxide KOH,

Potassium permanganate K₂Cr₂O₇