Programme 17: Atomic Structure

Answers to Activity Sheet 2

Amazing Atoms

Details of this activity can be found on the accompanying worksheet. The activity takes the form of a series of mathematical problems trying to give meaning to the very large and very small numbers involved in atomic structure. All the calculations can be done using a calculator with the numbers entered in non-standard form. However, if students are familiar with standard form then this should be used. Even when large numbers are entered in full, calculators are likely to give the answer in standard form. The worksheet contains information to allow the students to understand this. To extend the activity students could produce a poster about atomic structure, illustrating it with some of these amazing comparisons.

1. 10 000 000 × 0.75cm = 7 500 000cm = 7 500 000/100m = 75 000m = 75km

2. 50 000 000 000 000 000 000 000 × 0.0001m

= 5 000 000 000 000 000 000m (5 × 1018)

= 5 000 000 000 000 000km (5 × 1015)

3. 0.0000001/0.00000000000000000000000004
= 0.0000000000000000025 atoms
= 2.5 × 10 –18 atoms

4. 100m/100 000 = 0.001m = 1mm (about the size of a pin head)