Mass- Energy Equivalence

In 1905 , Einstein in his special theory of relativity suggested that mass is a form of energy. 

Einstein mass-energy equivalence equation is the basic formula that gives the basic relation between mass and energy

Rainbow 🌈 mind map

1. m= E/ c²  , means if  energy a body is increased by amount E , it's mass increases by m where m= E/ c².

Where c is the speed of light 3x10⁸ m/s.

The increased is too small but not zero .so, not noticeable. 

2. Equation  E = mc² states that the amount of energy possessed by an object is equal to its mass multiplied by the square of the speed of light. Since the speed of light is an lmost 3x10⁸ m/s, a small amount of mass contains a lot of energy.

3. 

 energy released / energy absorbed = mass lost x c²

4.

 Mass defect is the mass lost.

It is observed that mass of nucleus is less than sum of masses of all nuclons ( protons and neutrons)  making it.

5.

Amount of energy required to separate all nuclons from the nucleus or amount of energy released to combine nuclons in the nucleus is called binding energy

5.Stability of nucleus is  proportional to Binding energy/ nucleons

Elements between atomic nos between 50 to 80 are stable elements .Binding energy/ nucleon is about 8.5 Mev . Iron with atomic no. 56 is most stable element with B.E/ n  is 8.8 Mev

6. Elements with atomic number more than 50 , Binding energy per nucleon decreases . They are heavy nuclei and try to gain stability through Nuclear Fission.

7 .Elements with atomic number less than 50 , Binding energy per nucleon decreases . They are lighter nuclei and try to gain stability through Nuclear Fussion.