An atom W has 17 electrons and 18 neutrons. Which of the following representations of the atom is correct?

A.

1718W

B.

1817W

C.

3517W

D.

3518W

Correct answer is C

The superscript is the atomic mass = 35

(The mass number also called atomic mass number or nucleon number, is the total number of protons and neutrons)

 

The subscript is the atomic or proton number = 17

The number of electrons in a neutral atom is equal to the number of protons