Question

What are the terms that describe these values for the element oxygen?

Answer 1

Answer: 18 = Mass umber

8 = atomic number

Step-by-step explanation:

An atom is smallest unit of a matter or substance.It consist of three subatomic particles : electrons, protons, neutrons.

Protons and neutrons are located in the center of an atom where while mass of an atom is concentrated.

Mass number = Number of protons + Number of neutrons

Atomic number = Number of protons = Number of electrons (for a neutral atom)

General representation of an element is given as:
`_Z^A\textrm{X}`

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
`_8^(16)\textrm{O}`, thus 8 = atomic number and 18= Mass number

Answer 2

The 8 represents the Oxygen's Atomic Number. The 18 represents the Atomic Mass. The atomic mass is equivalent to the number of protons and neutrons in the element.