Question

In a Rutherford scattering experiment when a projectile of charge z₁ and mass m₁ approaches a target nucleus of charge z₂ and mass m₂, the distance of closet approach is r₀. The energy of the projectile is

(1) directly proportional to m₁ 

(2) directly proportional to m₁m₂ 

(3) directly proportional to z₁ z₂ 

(4) inversely proportional to z₁ z₂

Answer 1

Correct option : (3) directly proportional to z₁ z₂

Explanation :

When an particle is very far off it has only K.E (K). As it approaches the target its K.E decreases and electrostatic P.E increases. At distance of closet approach (r₀) the K.E. is zero. The entire energy is now electrostatic P.E. From law of conservation of energy