An alpha particle is equivalent to a nucleus. a .hydrogen b. helium c. lithium d. barium

B. helium

Explanation:

Alpha decay: In this process, alpha particles is emitted when a heavier nuclei decays into lighter nuclei. The alpha particle released has a charge of +2 units.

General representation of an element is given as: where,

Z represents Atomic number

A represents Mass number

X represents the symbol of an element

As the alpha particle has atomic number of 2 and mass number of 4, this is helium nuclei.

3 1/4 %

explanation:

the atomic number will stay the same no matter how many electrons it has, so it doesn’t decrease nor increase. it’ll only change with a different number of protons