Question

1. the atomic number of oxygen, 8, indicates that there are eight

a. protons in the nucleus of an oxygen atom.
b. oxygen nuclides.
c. neutrons outside the oxygen atoms nucleus.
d. energy levels in the oxygen atoms nucleus.

Explanation:

Define atomic number

$$ Z = \text{number of protons in the nucleus} $$

Apply to oxygen

$$ Z_{\text{oxygen}} = 8 \implies 8\text{ protons in the nucleus} $$

Match with options

$$ \text{Option a} \implies \text{protons in the nucleus of an oxygen atom} $$

Answer:

• a. protons in the nucleus of an oxygen atom. (Correct answer)
• b. oxygen nuclides.
• c. neutrons outside the oxygen atom's nucleus.
• d. energy levels in the oxygen atom's nucleus.