Question

question 3
5 pts
how many protons, electrons, and neutrons in oxygen with an atomic mass of 18
8 protons, 8 electrons, 7 neutrons
8 protons, 8 electrons, and 10 neutrons
9 protons, 10 electrons, and 7 neutrons.
8 protons, 8 electrons, 8 neutrons

Explanation:

Step1: Recall atomic number of oxygen

Oxygen has an atomic number of 8. The atomic number is equal to the number of protons and in a neutral atom, the number of electrons is equal to the number of protons. So, number of protons = 8 and number of electrons = 8.

Step2: Calculate number of neutrons

The formula for atomic mass is $Atomic\ mass=Number\ of\ protons + Number\ of\ neutrons$. Given atomic mass = 18 and number of protons = 8. Then number of neutrons = Atomic mass - Number of protons = 18 - 8 = 10.

Answer:

8 protons, 8 electrons, and 10 neutrons