Question

Which of the following observations indicates that an atom has neutrons?

Answer 1

Answer:

The correct answer is C: A radiation consisting of uncharged particles is emitted when alpha particles strike beryllium atoms.

Explanation:

Chadwick discovered neutron while experimenting with a gold foil. A stream of alpha particles produced from a polonium source was directed at beryllium target. It was noticed that some penetrating radiations were produced. These uncharged particles were called neutrons because on the charge detector these particles showed no deflection.

Their nuclear reaction is as follow.

                             ₂He + ₄Be ----------> ₀n + ₆C

Chadwick noticed that neutrons cannot ionize gases and are highly penetrating particles.

Answer 2

Answer: C. A radiation consisting of uncharged particles is emitted when alpha particles strike beryllium atoms.

A. Some uncharged particles are scattered by a beryllium atom when it hits a gold foil.

B. Some uncharged particles bounce back from a gold foil when it is bombarded with alpha particles.

C. A radiation consisting of uncharged particles is emitted when alpha particles strike beryllium atoms.

D. A radiation which attracts electrons is produced when a beryllium atom is bombarded with alpha particles.

Explanation:

I just took the test and the answer is C. A radiation consisting of uncharged particles is emitted when alpha particles strike beryllium atoms.

Good Luck!!