C2.1.1 Purity And Separating Mixtures

Question 1

What does a chemical formula tell you?

Answer 1

How many atoms of each element there are in a unit of a substance. For example, the chemical formula of water is H,O. This tells you that each molecule of water contains two hydrogen atoms and one oxygen atom joined together.

Question 2

Relative atomic mass?

Answer 2

Ar, is the mean mass of an atom of an element compared to 12/6 the mass of a C (carbon-12) atom.

Question 3

Relative formula mass?

Answer 3

Relative formula mass, Mr, is the mean mass of a unit of a substance compared to 1/12 the mass of a 12/6C atom.

Question 4

Relative formula mass?

Answer 4

Mr, is the mean mass of a unit of a substance compared to 1/12 the mass of a 12/6C atom.