Question

what is the atomic mass of an oxygen isotope that has 8 protons and 10 neutrons in its nucleus?
○ 8 amu
○ 10 amu
○ 18 amu
○ not enough information to calculate

Explanation:

Step1: Recall atomic mass formula

Atomic mass (amu) ≈ number of protons + number of neutrons

Step2: Plug in given values

Atomic mass = $8 + 10$

Step3: Calculate the sum

Atomic mass = $18$

Answer:

C. 18 amu