2007-01-14 03:56:01 · 3 answers · asked by Anonymous in Science & Mathematics ➔ Chemistry
figure out how many protons, neutrons and electrons are present. At this point you need to know that electrons are considered to have no mass. Protons and neutrons have a mass of one atomic unit each. Add up the number of protons and neutrons and you have your answer.
Ex. Hydrogen: 1 proton, 1 electron. Atomic mass for hydrogen=1
2007-01-14 04:08:30 · answer #1 · answered by A P 2 · 0⤊ 0⤋
The 'Atomic Mass (AMU)' of an element is the sum of the Protons and Neutrons. Protons have a mass of 1 as do neutrons.
If you look at the Periodic Table you will see the AMU as a decimal. That is because it shows the 'average' AMU of the elements isotopes.
Get an "A".
2007-01-14 16:13:54 · answer #2 · answered by teachr 5 · 0⤊ 0⤋
the easy way to know the atomic mass is to look on a periodic table :D ... find there atomic weight of an element
2007-01-14 12:03:07 · answer #3 · answered by mn3mosyne 2 · 0⤊ 0⤋