Question

If the Thomson model is correct what should be the observation in the $\alpha -ray$ scattering experiment

• A. All the $\alpha -ray$ should pass through the gold foil
• B. Only few $\alpha -ray$ should pass through the gold foil
• C. 98% of $\alpha -ray$ should get reflected back
• D. Both B & C

Answer 1

The correct option is A All the $\alpha -ray$ should pass through the gold foil

According to Thomson model, positive charge is uniformly distributed with electrons embedded in it like seeds of watermelon.

$\alpha$ ray is much heavier than proton as $\alpha {=}_2^{4}H{e}^{2+}$. Alpha particle has mass four times that of a proton. So since the positive charge is not concentrated in one place. So alpha ray will pass through the gold foil as there is no concentrated positive charge to stop it.

Hence, option $A$ would be the answer, if the Thomson model is correct.