Which of the following representations is correct for an atom X with 28 electrons and 30 neutrons?

A.

\(^{58}_{28}X\)

B.

\(^{30}_{28}X\)

C.

\(^{28}_{30}X\)

D.

\(^{58}_{30}X\)

Correct answer is A

An atom can be represented thus,

\(^{Z}_{A}X\) where Z = mass number

A = atomic number

A = number of proton = number of electrons in a free state = 28

Z = number of protons + number of neutrons = 28 + 30 = 58

\(^{58}_{28}X\)is the representation