Programme 17: Atomic Structure

Programme Questions: Activity Sheet 2

Amazing Atoms

• In this activity you will be finding out just how small atoms really are.
• You will be dealing with some very large and some very small numbers.
• If your calculator shows an answer like this 215 , it means 2 with 15 zeros after it (2 000 000 000 000 000).
• If your calculator shows an answer like this 2 -12 it means 11 zeros after a decimal point and then the 2 (0.000000000002).

1. Approximately 10 000 000 atoms could be fitted in a line across the full stop at the end of this sentence.

a) If the atoms were the size of peas (diameter 0.75cm) then, to the same scale, how wide would the full stop be in kilometres?
b) If your school were at one edge of this giant full stop, where might the other edge be?

2. In 1g of carbon there are about 50 000 000 000 000 000 000 000 atoms (that’s 5 with 22 zeros!).
If each of these atoms were the thickness of a page of a book, how thick would that book be?
(You can take the thickness of one page to be 0.0001m.)

3. A grain of sand weighs 0.0000001kg. If the atoms in sand weigh about 0.00000000000000000000000004kg (that’s a decimal point with 25 zeros followed by a 4), how many atoms are there in a grain of sand?

4. Most of an atom is empty space. The diameter of the nucleus is about 100 000 times smaller than the diameter of the whole atom.

a) If the atom is represented by the London Eye, how big would the nucleus be on the same scale? (The London Eye is about 100m in diameter.)
b) On this scale, which everyday object could be used to represent the nucleus?