How many different types of atom are there?
Why can you make millions of different substances from these different types of atom?
Why is it useful to have symbols for atoms of different element?
What are the names of the three particles that make up an atom?
An oxygen atom has 8 protons - how many electrons does it have?
What is the 14th element in the periodic table?
Where are the electrons in an atom?
Which shell represents the lowest energy level in an atom?
How many electrons can the first energy level hold?