Chemical Formula

Question 1

Key Rules of chemical formulas
1. Small numbers after the element symbol tell you the number of atoms of each element. No number means one atom
2. Capital and then lower case = one element
3. Capital and then capital = two elements
4. Brackets = times the number of of atoms inside the brackets by the number outside the bracket.

Answer 1

No question

Question 2

How many atoms per element are there in this formula?

Al (NO3) 3

(Italics = small numbers)

Answer 2

One atom of aluminium
Three atoms of nitrogen
Nine atoms of oxygen

Question 3

How many atoms per element in this chemical formula? (Italics mean small number)

CaCO3

Answer 3

One atom of calcium
One atom of carbon
Three atoms of Oxygen

Question 4

How many atoms per element in this chemical formula? (Italics mean small number)

MgSO4

Answer 4

One atom of magnesium
One atom of sulphur
Four atoms of oxygen