Question

For same kinetic energy which of the following particles have more momentum?

• A. Electron
• B. Proton
• C. Deuteron
• D. $\alpha$-particle

Answer 1

Answer: (D)

$\alpha$-particle

Momentum
$p=\sqrt{2mk}$
Where k is kinetic energy. In case of particles having equal kinetic energy
$p\propto \sqrt{m}$
Since m is maximum for $\alpha$-particle, hence momentum will be maximum for $\alpha$-particle.