question_answer

An \[\alpha \]-particle can be represented by a:

A)  hydrogen atom

B)         helium ion

C)         hydrogen ion

D)         helium nucleus

Correct Answer: D

Solution :

Alpha particles are composite particles consisting of two protons and two neutron tightly bound together as shown in figure. They are emitted from the nucleus of some radio nuclides during a form of radioactive decay, called alpha-decay. An alpha particle is identical to the nucleus of a normal (atomic mass 4) helium atom or a doubly ionized helium atom.