Laws of motion application

Newton's Laws of Motion - First Law Of Motion
Newton's Laws of Motion - Examples Of The First Law
Newton's Laws of Motion - Second Law Of Motion

The Newton first law of motion concentrates on a state of constant motion but adds unless an outside influence, force, acts on it. Force produces a change in the state of motion (velocity describes a body's motion); that is, an acceleration. Newton found that the greater a body's mass the greater the force required to overcome its inertia and mass is taken as a quantitative measure of a bod…

Newton's Laws of Motion - Applications Of The Second Law

For objects thrown upward, gravitational acceleration is still 32 ft/sec/sec downward. A ball thrown upward with an initial velocity of 80 ft/sec has a velocity after one second of 80-32= 48 ft/sec, after two seconds 48-32= 16 ft/sec, and after three seconds 16-32= -16 ft/sec (now downward), etc. At 2.5 seconds the ball had a zero velocity and after another 2.5 seconds it hits the ground with a ve…

Newton's Laws of Motion - Third Law Of Motion Or Law Of Action-reaction
Newton questioned the interacting force an outside agent exerted on another to change its state of motion. He concluded that this interaction was mutual so that when you exert a force on something you get the feeling the other is exerting a force on you. Newton's third law of motion states: When one body exerts a force on a second body, the second body exerts an equal and opposite force on …

Newton's Laws of Motion - Examples Of The Third Law
(1) What enables us to walk? To move forward parallel to the floor we must push backward on the floor with one foot. By the third law, the floor pushes forward, moving us forward. Then the process is repeated with the other foot, etc. This cannot occur unless there is friction between the foot and floor and on a frictionless surface we would not be able to walk. (2) How can airplanes fly at high a…

Read more: Newton's Laws of Motion - First Law Of Motion, Examples Of The First Law, Second Law Of Motion, Applications Of The Second Law http://science.jrank.org/pages/4658/Newton-s-Laws-Motion.html#ixzz0paAGxF7r

Sir Isaac Newton three Laws of Motion

Introduction :
In 1684, encouraged by his friend Edmund Halley, Sir Isaac Newton embarked on writing what was to be The principia mathematica was one of the greatest scientific works ever published. He enunciated the three laws of motion and the universal law of gravitation, which explained all the three Kepler's laws of planetary motion.
                    
In earlier times, motion of bodies was studied by philosophers. Most philosophers believed that a body moved with uniform velocity due to some external agent. They also thought that if there were no external agent the body would naturally come to rest. Galileo was the first to show that some external force was necessary to change the velocity of a body but that no external force was necessary to maintain the velocity of a body. This principle was adopted by Newton in his first law of motion.

Sir Issac Newton first law:

    The law enables us to define inertia and force. From this law it can be concluded that if the net external force on an object is zero, the acceleration of the object is zero.
Inertia ; If the net external force is zero, a body at rest continues to be at rest and a body in motion continues to move with uniform velocity. This property is called inertia. It is the resistance to change the state of uniform motion. Mass is a measure of inertia.  Ex: when the bus stops suddenly our feet stop due to the friction. But the rest of the body continues to move forward due to inertia of motion.
Force :  It is the physical quantity that changes or tries to change the state of rest or of uniform motion along a straight line.

Sir Issac Newton second law:

By Newton first law of motion, when there is no net external force on a body it moves with uniform velocity. In terms of momentum, the body will have constant momentum when there is no net external force on a body, Hence, when the momentum of a body changes the body must be under the action of a net external force.
           
Newton's second law of motion states that " The rate of change of momentum of a body is directly proportional to the resultant or net external force action on the body and takes place in the direction  in which the force acts" .
            
A body of mass m moving with velocity v is under the action of a net external force F in the direction of velocity. If its velocity is increased by `Deltav` in a time interval `Deltat`  then by the second law
                                                  F `prop` dp /dt             (or)                   F  `prop` d/dt (mv)        (since p = mv)
                               F = k d/dt (mv)                    , Assuming that the mass of the body is constant
                   F = k m dv/dt  =  k m a    , which shows that the net force is proportional to the product of mass and acceleration.
              
The proportional constant k is made equal to one, by properly selecting the unit of force. The SI unit of force is newton which is defined as the force that causes an acceleration for 1 ms^-2 on a body of mass 1 kg. Substituting k = 1 in F = k m a ,  we get
                                                    F  =  m a .
               The dimensional formula of force is [MLT^-2] .

Sir Issac Newton third law:

Newton's third law tells us about the origin of the force that causes acceleration. It states that " to every action, there is always an equal and opposite reaction " .
                     
In this statement, action and reaction are nothing but forces. When we hit a wall we apply  some force on the wall. An equal and opposite force acts on us due to the wall at the same instant of time. When we walk on the road we push the road backward and the road applies an equal and opposite force on us so that we can move forward. Newton's third law is not strictly applicable when the interaction between two bodies separated by a large distance is considered.

Newtons theory

NEWTON'S LOW OFUNIVERSAL GRAVITATION:-
The mechanisms of Newton's law of universal gravitation; a point mass m₁ attracts another point mass m₂ by a force F₂ which is proportional to the product of the two masses and inversely proportional to the square of the distance (r) between them. Regardless of masses or distance, the magnitudes of |F₁| and |F₂| will always be equal. G is the gravitational constant.

Newton's law of universal gravitation states that every massive particle in the universe attracts every other massive particle with a force which is directly proportional to the product of their masses and inversely proportional to the square of the distance between them. (Separately it was shown that large spherically-symmetrical masses attract and are attracted as if all their mass were concentrated at their centers.) This is a general physical law derived from empirical observations by what Newton called induction.^[1] It is a part of classical mechanics and was formulated in Newton's work Philosophiae Naturalis Principia Mathematica ("the Principia"), first published on 5 July 1687. (When Newton's book was presented in 1686 to the Royal Society, Robert Hooke made a claim that Newton had obtained the inverse square law from him – see History section below.) In modern language, the law states the following:

Every point mass attracts every single other point mass by a force pointing along the line intersecting both points. The force is directly proportional to the product of the two masses and inversely proportional to the square of the distance between the point masses:^[2]

where:

·         F is the magnitude of the gravitational force between the two point masses,

·         G is the gravitational constant,

·         m₁ is the mass of the first point mass,

·         m₂ is the mass of the second point mass, and

·         r is the distance between the two point masses.

Lorentz force

Proof of Faraday's Law
It is evident from Faraday's experiments that whenever there is a change in the magnetic flux passing through a closed circuit, an electric current is induced in the circuit. It can be explained on the basis of Lorentz force.

Suppose a conducting-rod JK (Fig. 7) is being moved without friction on the arms of a U-shaped stationary conductor MNOL with a velocity v towards right. The conductor is situated in a magnetic field B perpendicular to the plane of paper directed downwards. Due to the motion of the conducting-rod, the free electrons present in the rod are acted upon by a magnetic (Lorentz) force F_m of magnitude qvB which takes the electrons from the end J of the rod to the end K. Since a closed circuit is available to the electrons, they drift along the path J-*K-*O^N-*J. Thus, an electric current is established in the circuit along J->N->0->K-*J (anticlockwise)*. So long the rod JK is kept moving in the magnetic field, the electric current continues to flow in the circuit. It means that an emf is induced in the moving rod which maintains the current in the circuit. Since this emf induced in the rod is due to the motion of the rod, it is also called as the 'motional emf. It is due to the Lorentz forces acting on the free electrons in the moving rod.

Suppose, the induced emf in the moving rod JK is e and the induced current in the circuit is i. We know that when a current-carrying conductor is in a magnetic field, it is acted upon by a force in a direction given by the Fleming's left-hand rule. The magnitude of the force imposed by the magnetic field B on the current-carrying rod JK is given by
F' = i IB,

where I is the length of the rod JK. The force F*' is directed towards left. Hence, to keep the rod moving with a constant velocity v towards right, a force F equal and opposite to F' will have to be applied on it; that is
F = -F' = -ilB.

Suppose, under the force Ft the rod JK undergoes a displacement Ax* in the direction of the force in a time-interval At and comes in the position J 'K'. Then, the work done on the rod will be given by
W =F*.Ax*= F Ax = -HB Ax. But A* = v x Af (magnitude of velocity x time-interval).
W = -HBvAt.
But i x At = q (charge flown through the circuit in time At)
W = -Bvlq.

This work provides the necessary energy for the flow of charge in the circuit. We know that the energy supplied by a cell in flowing unit charge through a circuit is called the emf of the cell. Hence the induced emf e in the rod / K (which is working as a cell in the circuit J N O K J) is given by
e = W/q = - Bv I. ...(i)

In the time-interval At, the area of the circuit increases from JNOKJ to J' N O K' JHence, during this time-interval, the change in the magnetic flux passing through the circuit is given by
A<P_b = magnitude of magnetic field x change in area (JJ 'K'K) = B x (I x Ax).

Hence the rate of change of magnetic flux is
AO_fl Ax
I — O I ~~ .
At At
But Ax/At = v (velocity of the rod). Thus
-tf'Blv. ...(ii)
Comparing eq. (i) and (ii), we get
A<D_fl
^{e =} -~AT■
In the limit At —» 0,
d<b_B
^{e =} ~~dT■

This is Faraday law of electromagnetic induction.

The negative sign signifies Lenz's law. The direction of current (anticlockwise) in the circuit due to the induced emf e is such that the force imposed on the rod (due to the current) opposes the motion of the rod (the motion of the rod is the cause of the current).

It can be seen in the other way also. The direction of current in the circuit is such that the magnetic field produced due to this current is just opposite to the original field B. That is, it opposes the increase in the magnetic flux passing through the circuit (the increase in the magnetic flux is the cause of the generation of current). We may see it from any point of view, the direction of the induced current is always such that it opposes the very cause of its production. This is Lenz's law.

Dimensions of Induced E.M.F.: Numerically, we have
d<b_B ^{e =} ~dT-
, dimensions of e = ₌ ^T^A'*] _{= a} , _A_,
dimensions of t [T]

Organic chemistry articles

Introduction:-
The study of chemistry of carbon compounds is called organic chemistry. According to Lavoisier that all compounds obtained from vegetables and animal sources always contained carbon and hydrogen mainly and nitrogen and phosphorous are also found in some compounds. According to Berzilius organic compounds  are produced from plant and animals only due to presence of some vital force in them.It is called  “Vital force theory”.It is disproved by wholer by producing urea(NH₄ CONH₂) from ammonium cyanate (NH₄CNO)
                                                                 NH₄CNO→ NH₄ CONH₂  
                                   Kolbe synthesized acetic acid (CH₃COOH) from its elements.

Compounds:-

Carbon form millions of compounds due to the following reasons.
1.    High catenation
2.    Tetravalency
3.    Ability to form multiple bonds
4.    Ability to exhibit isomerism

Classification of organic compounds based on carbon skeletion
                     Carbon compounds
Open chain(acyclic)                 (cyclic) closed chain
Aliphatic
Saturated    Unsaturated

Alkanes        Alkenes    Alkynes
Alkanes: Open chain compounds with single bonds between carbon atoms
Ex:  methane and ethane
Alkenes: open chain compounds with atleast one double bond in the carbon chain
Ex: ethylene,propylene
Alkynes: open chain compounds with atleast one triple bond in the carbon chain
Ex:  acetylene,propylene
Alicyclic: Carbon ring with single bond between carbon atoms
Ex: Cyclohexane C₆H₆
Aromatic: planar ring structures with (4n+2)∏ electrons  are called aromatic  according to Huckel rule.Where n is 0,1,2,….
    Ex: pyridine,Furan.

Classification of Carbon compounds on the basis of functional groups:-

Atom or bond or group of atoms in a molecule which is responsible for the characteristic properties of the compound is called functional group

Name	General Formula	Name	Structural Formula
Alkanes	CnH2n+2	Ethane
Alkenes	CnH2n	Ethene
Alkynes	CnH2n-2	Ethyne

Natural Organic Soap

Introduction :
Soap is made by heating animal or vegetable oils with sodium hydroxide. Esters present in fats are broken down to glycerol and sodium salt of fatty acid.

Fat + Sodium hydroxide ------------> Soap + Glycerol

This reaction is called saponification.
Let us discuss the cleaning action of natural organic soap in detail:

Cleaning Action of Natural Organic Soap

The cleaning action of natural organic soap depends on its structure.
E.g. Sodium stearate consists of a long hydrocarbon chain which is hydrophobic (water-hating), attached to an ionic head, which is hydrophilic (water - loving). These molecules dissolve in water because of ionic end to the molecule.

When dissolved in water, the soap molecules lower the surface tension of the water, makiang it wet objects more easily. The molecules also interact with grease and dirt present in the cloth. The hydrophobic hydrocarbon chain is attracted to the grease and become embedded in it. The hydrophilic head of molecule points away from dirt and is attached to water molecule. When water is agitated, the grease is released from the cloth fibre or dish and is completely surrounded by soap molecules. Rinsing with fresh water removes this grease. The use of soap in hard water creates lots of problems because it forms scumbs with hard water. But nowadays synthetic detergents are available which do not scumb witrh hard water. Sodium alkylbenzene - sulphonates were developed in 1970s.

They have a similar long hydrocarbon chain to soap molecules, but the ionic group at hydriphilic head has been changed. The early synthetic detergent molecules were not biodegradable and cause pollution problems in rivers and streams.

Uses of Natural Organic Soap:

• Natural organic soap can be used to avoid or reduce many skin problems.
• Its ingredients have been produced without using fertilizers or pesticides, so it is not harmful to the skin.
• It leaves our our skin feeling clean and moisturised.
• Glycerine, which is a great moisturizer is retained by the natural organic soaps.
• Reduction in the use of toxins helps to create better living environment.
• Most of them are also free from animal fats, which prevents the killing of animals.

Organic chemistry spectroscopy

Introduction 
The study of the interaction between radiation and the matter is called spectroscopy. Molecules in an organic compound have the tendency to absorb specific frequencies according to their structural characteristics. These frequencies can be in the range of visible light, infrared or ultraviolet radiations.

Description of organic chemistry spectroscopy

The electrons in the molecules of an organic compound undergo transition when they absorb or emit light. This is the reason that the color perceived by the organic compounds depends on the absorption of light radiations in the visible range.

Infrared spectroscopy is very successful in organic chemistry.  The types of bonds present in a compound as well as their lattice arrangements can be found by the absorption of IR radiations when they emit thermal radiations. The frequency at which the absorption of the radiation takes place matches the frequency of the vibrating bond.

Nuclear magnetic resonance spectroscopy analyzes the magnetic properties of certain atomic nuclei like hydrogen and carbon which determines their local environments in an organic compound through which the structure of the compound can be determined.

UV spectroscopy is used in highly conjugated organic compounds which absorb UV light or light in the visible regions. When electrons within the atoms are excited from one electronic state to another, their solutions show change in color based on changes in the wavelength due to absorption of visible light by the d electrons. Organic compounds with solvents may either have significant or weak UV absorptions because the pH value and polarity of the solvent do affect the absorption capability of the organic compound.

By passing a beam of IR light through a sample of organic compound the infrared spectrum of the sample can be recorded. On examining the light rays that are transmitted, we get to measure the quantity of energy absorbed at each wavelength. Absorption takes place when the IR frequency is equal to the frequency of the bond. Analysis of these absorption characteristics reveals details about the molecular structure of the sample.

Conclusion for organic chemistry spectroscopy

As complex molecular structures lead to more absorption bands which in turn develops more complex spectra, various types of spectroscopy techniques help in characterization of complex mixtures.

Electricity wind

Introduction

Electric power:- As we know Electric power or elctric current both are same, you have learnt that uncharged boby can be charged by connecting body with a metal wire. In the process of tranfer, charge flows through the wire in a fraction of a second. The flow of electric change constitues an electric currect. With electric power we can run anything like fans, ac , refrigerators, machines, computer almost all the mechanical things you can run by electric power. So electric power is very much important in our daily life.

We are using eletric power almost every second of our daily life and we cannot live without electric power. As we know electric power is not a renewable source of energy we need to produce it own your own. So we have wind energy which is renewable source of energy with the help of wind energy we can produce electric power. This picture show about electric power.

Electricity wind

Wind power :- With the help of wind power we can produce electric power as we know wind blows with the natural phenomenon and we need to source to blow fast wind. Because of different temperature on earht surface wind blows from one direction to another direction and we can utilize this wind energy in different purposes as we can set up a wind turbine and with wind power these turbines will rotate and it will produces mechanical energy and we can use this mechanical energy in any form we can use it by grinding grains , pumping water and most important we can produce electric power by wind energy, just by connecting wind trubines to electric generator we can convert mechanical energy to electrical power. Following figure shows you the image of wind turbine.

Advantages of electric wind power

    As is it renewable source of energy we can produces as much as electric power with the help of wind power just we need to fix wind turbine.
    This is very cheap source of energy and we can produce large amount of electric energy with the help of wind power.
    We can use electric energy produce by wind power in any form.

Static and Current Electricity

Introduction :

The two basic kind of electricity that exist in nature are:  the static electricity and the current electricity.Static electricity is nothing but the collection of uncontrolled electrons which are passing from one body to another body in a movement which is sudden or momentary. Whenever the motion of the electron along a path is a controlled motion then the electricity so produced in the system or circuit is the current electricity.

Examples of static and current electricity

The examples of static electricity:

    The clothes taken out from the dryer and they are stick together

    One can get a shock after walking on the carpet and then suddenly touching something.

The static electricity is generally a nuisance and the hazards of static electricity include the cause of fire. The example of static electricity in which it is produced by rubbing the balloon with the hairs.

Static electricity

Example of current electricity:

The path used in the case of the current electricity is generally a conductor of electricity like a copper wire which can move the electricity from the power plant to the households

Current electricity

Application of Static and Current Electricity

The current electricity is obtained in case when a plug is inserted in a socket, which is generally seen in our homes and this electricity is used to power up the systems like the stereo and the lights. The current electricity is the flow of billions of electrons through the circuit and this flow of electron make a wave of electron which has a voltage of about 120 V. The flow of the current electricity in a system can be taken as the pushing of the electrons through the system through a wire and on the wall on which the socket of electricity is located.

On the other hand, the static electricity occurs only when some of the electrons of a neutral material are moved from their present location to some other location and hence give rise to the electricity and the motion of electron is due to some unknown causes and this electricity is not generally observed. In case of the static electricity no new electron is involved to produce electricity only those electrons which are already there are undergoes some changes hence produces electricity.

A day without electricity

Introduction

A day without electricity is very difficult. Imagining a day without electricity thinking it will be very difficult

Imagine a day without electricity, not just a brief power outage. We all know how inconvenient that day becomes when our electricity is out for only a few hours. How hard it is to remember for that short period of time that the light switch will not produce instant light, the hair dryer will not immediately blow dry our hair, or that we can't even run water into our homes. Our homes and lives have become so dependent on electricity it is really hard to imagine everything that would change without it.

In details

Lifestyles in our own Ozark Mountain region have changed dramatically with the invention of electricity and its establishment into our everyday lives. Have you ever noticed a log cabin built at the very top of a high mountain where it would have a beautiful view? Probably not. Locations were chosen for homes because of accessibility to water, preferably a big spring. Having your home close to a spring meant having cold milk, a cool watermelon in the summer, and plenty of drinking water. Before electricity, a "spring box" would be constructed where the cool spring water would run into it and be deep enough to cover containers of milk, butter, etc. I'm convinced that a spring located close to your home was just about one of the biggest luxuries in those days. Remember, without electricity there were no electric cattle waterers. Drawing water from the well by hand to water a herd of cattle and horses would now seem an impossible task.

A day without electricity
Can we really imagine doing laundry without electricity? Carrying water from the spring, or drawing enough water from the hand-dug water well could prove to quite a day's chore. We really can't imagine the time and effort put into doing a mere "load of laundry" before our electric washers and dryers.

Periodic table alkali metals

Introduction :   

Elements belonging to group 1in periodic table are called alkali metals.  Their outer most electronic configuration is ns1 in periodic table.

Z        Element        No. of electrons

1         Hydrogen             1

3         Lithium                2, 1

11       Sodium               2, 8, 1

19       Potassium           2, 8, 8, 1

37       Rubidium            2, 8, 18, 8, 1

55      Caesium              2, 8, 18, 18, 8, 1

87      Francium             2, 8, 18, 32, 18, 8, 1

The group in a periodic table also includes hydrogen because of the similarity in the electronic configuration with these elements.  They are called alkali metals since they readily dissolve in water to form soluble hydroxides which are strongly alkaline in nature.  The word alkali has been derived from the Arabic word alquili, which means the ashes of plants from which certain compound of the elements sodium and potassium were initially isolated.  Sodium and potassium are abundant while the remaining elements occur only in traces.  The last element francium is radioactive and unstable. 

Alkali metals of periodic table:

They have maximum value of atomic radii, form monovalent  cations and possess the lowest ionization enthalpies  Their hydration enthalpies are low due to their large size. They have low electro negativities and all the members are strongly electro positive.They possess +1 oxidation state, and have low melting and boiling points. They are very light and impart characteristic colors to the flame.They exhibit photoelectric effect. 

They are highly reactive chemically because of their low ionization enthalpies and enthalpy of atomization. They are normally kept in chemically inert solvents such as kerosene.  They form oxide when they combine with oxygen and hydroxide when they react with water.The reaction with water is highly exothermic.So, alkali metals are not kept in contact with water.All alkali metals combine with hydrogen upon heating to form colorless crystalline hydrides that are ionic in nature.They combine with halogens directly to form metal halides. The alkali metals are powerful reducing agents.They are soluble in liquefied ammonia.They react with sulphur and prosperous upon heating to form the corresponding sulphides and phosphides.  

Hydrogen atom consists

Introduction

A hydrogen atom consists of an atom of the chemical element hydrogen. It is an electrically neutral atom which contains a single positively-charged proton and a single negatively-charged electron and they are bound to the nucleus by the Coulomb force. Hydrogen-1, protium, or light hydrogen is the most abundant isotope and it contains no neutrons. There are other isotopes of hydrogen, such as deuterium which contains one or more neutrons.

Niels Bohr in the year 1914 got hold of the spectral frequencies of the hydrogen atom subsequent to making a number of straightforward assumptions. The assumptions were not fully right but they gave up the proper energy answers.

Schrödinger equation and Hydrogen atom

The confirmation of the Bohr's results for the frequencies and underlying energy values were done using Schrödinger equation between the years 1925-1926. The clarification to the Schrödinger equation for hydrogen is systematic. This equation can be used to find out energy levels and thus the hydrogen spectral lines frequencies can be measured. The explanation of the Schrödinger equation goes much advance than the Bohr model nevertheless, for the reason that it also gives way to the shape of the electron's wave function ("orbital") for the various possible quantum-mechanical states, thus clearing up the anisotropic character of atomic bonds. This equation for the hydrogen atom is based on the fact that the coloumb potential which is produced by the nucleus is isotropic in nature. It is radially symmetrical in space and depends on the distance to the nucleus. The resulting eigen energy functions are not isotropic themselves.

Hydrogen ion

In ordinary chemistry, hydrogen is not found without its electron at room temperatures and pressure. Ionized hydrogen is written as "H⁺". Ionized hydrogen in case of the salvation of classical acids like hydrochloric acids forms hydronium ion. Hydronium ion is written as H₃O⁺. This refers to the entire hydronium ion and to a single ionized hydrogen atom. In this type of case, the proton is transferred by acid from water to the hydronium ion. This type of ionized hydrogen without their electron or free protons is commonly observed in the solar wind and interstellar medium

The nucleus of an atom contains

An atom is constructed of three major particles; two of them are in a central region or core called the atomic nucleus. The third type of particle is in the region surrounding the nucleus. The weight or mass of the atom is concentrated in the nucleus. The nucleus of the atom contains the protons and the neutrons, which are the massive particles of the atom. One type of particle located in the nucleus is the neutron.

Introduction 

Neutrons were named to reflect their lack of electrical charge. They are neutral. Protons, the second type of particle in the nucleus in certain areas called  enegry levels are the electrons. Each electron has a negative electrical charge. The number of electrons determine the space that an atom occupies.

Charge of an atom

The charge of an atom is neutral if the number of positively charged protons equals the number of negatively charged electrons. For instance, hydrogen with 1 proton, would have 1 electron; carbon with 6 protons would have 6 electrons. You can determine the number of either of these two particles in a neutral atom if you know the number of other particles.

Identity of the element
All the atoms of the same element have the same number of protons. The number of protons determine the identity of the element. For example, carbon always has 6 protons and no other element has that number. Oxygen always has 8 protons. The atomic number of an element is the number of protons in an atom of that element; therefore, each element has a unique atomic number. Because this is an extremely small mass and is awkward to express, 1 proton is said to have a mass of 1 atomic mass unit.

Neutral atoms
Although all the neutral atoms of the same element have the same number of protons and electrons, they do not always have the same number of neutrons. In the case of oxygen, over 99% of the atoms have 8 neutrons, but there are others with more or fewer neutrons. Each atom of the same element with a different number of neutrons is called an isotope of that element. Since neutrons have a mass very similar to that of a proton, isotopes that have more neutrons will have a greater mass than those that have fewer neutrons.

Isotopes
Elements occur in nature as a mixture of isotopes. The atomic weight of an element is an average of all the isotopes present in their normal proportions. For example, of all the isotopes present in their normal proportions. For example, of all the hydrogen isotopes on Earth, 99.985% occur as an isotope without a neutron and 0.015% as the isotope with one neutron.There is a third isotope with two neutrons but it is not considered because it is highly unstable. When the math is done to account for the relative amounts of the various isotopes of hydrogen, the atomic weight turns out to be 1.0079 AMU.

Mass number of an atom
The sum of the number of protons and neutrons in the nucleus of an atom is called the mass number. Mass numbers are used to identify isotopes. A hydrogen atom with 1 proton and 1 neutron has a  mass number of 1 + 1, or 2, and is reffered to as hydrogen-2 ( also called deuterium). A hydrogen atom with 1 proton and 2 neutrons has a mass number of 1 + 2 , or 3, and is referred to as hydrogen-3 ( also called tritium).

3 particles of an atom

Hi There are 3 main particles of an atom. They are electrons, protons and neutrons.

Introduction to 3 particles of an atom

Protons
Protons are the most elementary particles of an atom.
They are situated in the nucleus.
They carry single positive charge.
In fact, charge carried by a proton has been labeled as single charge.
How do all the protons, which are similarly charged stay composed in the nucleus?
It is because of energy called binding energy.
The number at the base of an atom represent the atomic number.
e.g.In case of carbon ₆C, the atomic number is 6, which means number of protons is 6.

Neutrons

They are nuclear particles with mass nearby that of protons but no charge.
Since they are part of mass number along with the protons, the number of neutrons is equal to,
Mass number - Number of protons.
e.g: The mass number of Krypton is 84 and the number of protons is 36.
So the number of neutrons =  84 - 36 = 48
Mass number is written at the top of the symbol of the element.

Electrons

Electrons are negatively charged subatomic particles.

The charge is −1.602×10⁻¹⁹ Coulomb.
Their mass is 1/1836 ^th of that of proton and is many a times neglected in related calculations.
Electrons are rotating outside the nucleus of an atom. They are arranged in sub-shells in different energy levels.

The energy levels are named as K, L, M, N etc.., and the sub-shells as s, p, d, f etc.., Electrons posses a spin of +1/2 or -1/2.

Electrons are elementary particles and are not composed of quarks. They were discovered by J.J.Thompson in 1897.

Electricity is actually flow of electrons.
Chemical bonds are formed either by donating, accepting or sharing of electrons.
As the number of electrons is same as that of protons, the atom attains stability as the opposite charges attract one another.
Thus the number of electrons can be found from the number of protons.

Iron atom

Introduction 

Iron atom is a chemical element having atomic number 26 and with the symbol ‘Fe’ which in Latin means ferrum.  It is a metal in the first transition series.  Like other ‘group 8’ elements, it exists in several oxidation states. The oxidation states of iron is +2 and +3, it might also occur in higher oxidation states of about +6.  Iron (II) compounds are called ferric and iron(III) compounds are called ferrous.   Iron and its alloys are the widely used ferromagnetic materials in the modern day life.

Pure iron is softer than aluminum.  Steel can be prepared by alloying pure iron with small amounts of other metals and carbon. The alloy steel is almost 1,000 times harder than pure iron.  It is the most common element found on earth.  It reacts with air to form iron oxides also known as rust. The rusting of iron and its alloys is undesirable, and has a major economic impact. The melting point of iron is about 1535 °C. Its mechanical properties can be varied extensively by varying the carbon content in the alloy.

      Different types of Iron are

1.   Pig iron has 3.5–4.5% carbon
2.   Cast iron contains 2–4% carbon 
3.   Wrought iron has less than 0.008% carbon

Occurrence and Biological Importance of Iron atom

Occurrence of Iron atom: Iron is the fourth most abundant element in the Universe, formed from the process known as nucleosynthesis, by the fusion of silicon in huge stars. Metallic iron is rarely found on the surface of the earth because it tends to oxidize, but its oxides are diffused and represents the primary ores. About 5% of the earths curst constitutes of Iron.  Most of the Inner and outer core of earth consists of Iron-Nickel alloy which is about 35% of the total mass of the earth.  Hematite and Magnetite are the most common form of iron ore which is found in earth crust. These ores are combined with oxygen to form iron oxides. 

Biological importance of Iron atom: Iron plays a major role in biology.  Ranging from the primitive archaea to humans, all living organism has iron-proteins.  Hemoglobin is a protein containing iron.  Hemoglobin is responsible for the color of the blood.  Hemoglobin and myoglobin are the two compounds which helps in the transportation of oxygen proteins in vertebrates.  Iron is present in each and every cell of the human body. It is the basic necessity for the growth and development of a living organism.

Applications of Iron