Question

How to calculate atomic mass?

Answer 1

Protons and neutrons?

Answer 2

or electrons

Answer 3

Atomic mass is calculating by adding the number of protons and neutrons (each has a mass of one amu). Electrons are almost 2000 times smaller than either and so their mass is usually insignificant when calculating atomic mass.

Answer 4

Depends on how they want you to approach it. Amu can be determined by the abundance of different elements. i.e.:

Carbon-12 90%
Carbon-13 6%
Carbon-14 4%

Multiply the masses by the percents of abundance and sum them up to find your atomic mass.

Answer 5

look at a periodic table