calculations Flashcards
1
Q
how to work out no. of neutrons
A
mass - atomic = neutrons
2
Q
isotopes
A
same no. of protons but different no. of neutrons
3
Q
what is a mole?
A
a mole of any substance always contains same no. of particles
4
Q
how do you work out the relative formula mass?
A
times the top no. by the amount of of substances there are for that particular substance ( and no.s together if there are lots)
5
Q
how do you work out the % mass?
A
divide the particular substances relative formula mass by the total formula mass and then x100
6
Q
how do you work out the empirical formulae?
A
divide the % mass by the atomic mass for both different substances, and divide both by the smallest answer u just got, then if u get 4 it means e.g H4