Question

The atomic mass in Phosphorus is a decimal because __________. Neutrons aren't always the same mass. It is charged. proton number varies. It is the average mass of all phosphorus elements in nature.

Answer 1

"It is the average mass of all phosphorus elements in nature."

Step-by-step explanation:

I don't really know why, I just got it right on this quiz with this answer. Hope it helps :)