C1 Chemistry - % of mass and empirical formula

Question 1

what is a simple way of describing the relative formula mass

Answer 1

add up all the relative formula atomic masses

Question 2

how do you work out the % mass of an element in a compound?

Answer 2

relative atomic mass x no* of atoms
____________________________ x 100
relative mass

Question 3

what are the 5 stages of finding the empirical formula

Answer 3

1. list all elements in the compound
2. write their masses or percentage
3. divide each mass or % by the relative atomic mass
4. multiple or divide by well chosen no*s
5. get the ratio to simplest form
   that tells you empirical formula of the compound