A potassium (K) atom has 20 neutrons, 19 protons and 19 electrons. What is the atomic mass of potassium?
19 20 38 39
Question: A potassium (K) atom has 20 neutrons, 19 protons and 19 electrons. What is the atomic mass of potassium?
A. 19
B. 20
C. 38
D. 39
Answer: