Respuesta :

The "8" represents Atomic Number & the "18" represents Atomic Mass.

Answer: 16 represents Mass number and 8 represents Atomic Number.

Explanation:

General representation of an element is given as: [tex]_Z^A\textrm{X}[/tex]

where,

Z represents Atomic number

A represents Mass number

X represents the symbol of an element

Oxygen is the 8th element of the periodic table and is written as [tex]_8^{16}\textrm{O}[/tex]

where,

16 represents Mass number and 8 represents Atomic Number.