Answer:
B. 8 e-, 8p+, 10n0
Explanation:
For the Oxygen-18 isotope,
Mass number = atomic number + number of neutron
For an electrically neutral atom, the number of proton is the atomic number.
Mass number = number of proton + number of neutron
The mass of proton is the same as the mass of neutron but the mass of a electron is negligble.
For isotopes, atoms with the same atomic number but different neutron numbers, hence different mass numbers.
Mass number of O-18 = 18
Atomic number of oxygen = 8
Number of neutron = 18 - 8
= 10
Number of proton = 8
Number of electron = 8
Therefore, 8 e-, 8p+, 10n0