L1-3 Recap key principles about atoms

New material need to introduce for F pupils / material to recap if H pupils
 
Atoms are very small, having a radius of about 1 × 10-10 metres.
The radius of a nucleus is less than 1/10 000 of the radius of an atom.
Atoms are very small, having a radius of about 0.1 nm (1 x 10-10 m).
 
The radius of a nucleus is less than 1/10 000 of that of the atom
(about 1 x 10-14 m).
 
Students should be able to relate size and scale of atoms to objects
in the physical world.
 
Students should be able to relate size and scale of atoms to objects
in the physical world.
For electron structures - Students may answer questions in terms of either energy levels or shells.