Question

how do you find atomic (molecular) mass?
by adding the number of protons and neutrons in the nucleus
by doubling the number of protons in the atom
by subtracting the number of electrons from the number of protons
by adding the number of protons and electrons together

Explanation:

The atomic (molecular) mass is approximately equal to the sum of the number of protons and neutrons in the nucleus since protons and neutrons have a mass of about 1 atomic mass unit each, while electrons have negligible mass compared to them.

Answer:

By adding the number of protons and neutrons in the nucleus