22.1 The atom . . . . . . . . . . . . . . . . . . . 237 22.2 Structure of an atom . . . . . . . . . . . . . . 238 22.3 Electronic structure of an atom . . . . . . . . . 241
Why it matters
All the matter in you and around you is made of atoms. The structure of these atoms tells us whether the matter they make up is a metal, like iron, or a gas, like oxygen. The more we know about the structure of atoms, the more we can predict how they will react together to form new compounds.
22.1 The atom Activity
How small can you go?
Take a strip of paper 28 cm long x 1 cm wide and cut it in half as many times as you can.
Questions 1. How many cuts did you make? 2. Take the smallest piece of paper and compare it with the width of a human hair. If you cut your original piece of paper in half 12 times it would be the width of a human hair. If you cut it 19 times it would be the width of a visible light wave. If you made about 30 cuts you would reach the smallest particle of the paper that still is paper!
LO 3 Chemical World strand LO 1 Nature of Science strand
