3. Atom and its characterstics...

    In previous blog we have discussed about Atom and its parts i.e. inner nucleus and outer space(electron cloud).Now we have to know that what is electron, proton  and  neutron,and which type of charges they have, and what are the explanations behind it?

Electron proton and neutron are also called fundamental particle of an Atom.

Electron-(symbol e⁻)

              It is discovered by j.j. Thomson.An electron is a subatomic part with a negative charge,having very small or negligible mass (approximately 9.109×10⁻³¹ kilograms) in comparison to proton and neutron.This mass is called the rest mass of an electron.

Charge on an electron is(−1.602×10⁻¹⁹ coulomb).  It is  determined by Millikan,in 1939 by using "Oil drop technique".  An electron is also the smallest charge of electricity i.e. unit negative charge.

Proton-( symbol p or p⁺)

            Proton was discovered by Ernest Rutherford in 1911 .Experiment with discharge tube containing perforated cathode indicates the presence of another type of rays that passed through the hole in cathode and carried positive charge,these rays were called Anode rays.

The determination of  ratio of charge to mass (e/m) by using different gases in discharge tube shows that Hydrogen gas gave highest value for e/m,it indicates that if  mass of each gas is same then mass of hydrogen gas is the lowest.it proves that hydrogen is the smallest fundamental particle having a positive sign to that of electron.This lightest positive particle is known as Proton.Mass of proton-1.672621×10⁻²⁷ kg

Charge of proton-1.602176565(35)×10⁻¹  Coulomb

Number of proton is called as Atomic number of an atom(or the number of electron present out side the neucleous).

Neutron-( n or n°)

      It is discovered by Chadwick in 1932.When thin sheet of boron or beryllium was bombarded by alpha particles,a stream of new particle which carried no charge  but had a mass almost equal to that of proton, was emitted.These neutral particles are called neutron. 

 

Mass of neutron-1.674927351(74)×10⁻²⁷ kg.

It is important to mention that the neutron was not discovered until 1932 when James Chadwick used scattering data to calculate the mass of this neutral particle.

If you have any confusion or question please send .

1. What is Chemistry...!!!

Chemistry

          What is chemistry?  It was a mystery but now a days there are various sites and books which can explain it better which can help us to understand chemistry and its reactions but the question is that why CHEMISTRY is still a mystery for the students while all the materials, facilities are available, everything is written in books, but it is still confusing what is not written the books that is...how to understand chemistry?

             Lets try to understand chemistry and its fundamentals with CHEMOLINE and say that chemistry is not a mystery.

      First of all we should focus on basic concepts -

• What is chemistry? 

            Chemistry explains about the composition , property and behaviour of matter.It also explain the interaction between matter and energy ..we can also say that  matter ,energy and interaction between them is chemistry.. simple...!!! huh...? No...to make it simple one should know what is matter, what is energy and what does it mean  by interaction etc... Don't worry, we'll try to understand each and everything that we encounter in our Chemistry Safari...(at least we'll try to and if you find anything missed, please post your comment and i'll definitely cover that in my upcoming posts).

Lets start with basics..

Matter-

         Object which have Mass, more specifically, they must have rest mass, which is a form of energy that matter has even when it isn't moving...it has no kinetic energy neither thermal energy. It is made of tiny particles called atoms. The atoms have spaces between them and move or vibrate all the time. The particles move faster and move further apart when heated and reverse when cooled...

Energy-

      It is a word with more than one meaning. Energy means something has to change. In science, energy is something that can do work...There are two type of energy- kinetic energy and potential energy.

kinetic energy- this is the energy a body has because of its motion

                              K.E.= 1/2mv²

where                   m= mass, v= velocity of the moving body

                

Potential energy- it is stored energy of a body which helps to move.

                              

                            P.E.= mgh (m= mass, g= acceleration due to gravity, h= height)

Chemistry is devided in 3 different types--

1. Physical chemistry-  Study of macroscopic, atomic, sub atomic, particulate phenomena in chemical system in terms of law and concept of physics.  It applies the concept of physics like motion ,  energy, thermodynamic etc..

2. Inorganic chemistry- Study of synthesis and behaviour of inorganic and organometallic compounds.

3. Organic chemistry-It involves  study of structure, property and reaction of organic compounds.

We will discuss about atom,composition and some more basic concepts in my next blog....