Atomic mass= number of protons + number of neutrons
hope this helps
Desireurban has given a good discussion in the first answer,
but be careful with it:
-- Yes, skimming instead of reading carefully can be non-productive.
-- Using credible sources is MORE productive, and using less reliable sources
can be LESS productive.
Another nonproductive learning behavior ... one that I worry about a lot ...
is slapping the question up on Brainly and waiting for someone to give
you the answer, instead of taking some time to think about it.
