Two big groups

About this video

Iron, copper and gold are elements. So are oxygen, carbon and sulfur, but they are nothing like the first three. Chemists sort the elements into two big groups: metals and non-metals.

A metal is shiny when it is clean or freshly cut. It carries heat and electricity well, which is why pots and electric wires are made of metal. It bends: you can hammer it flat or pull it into a wire without it breaking into pieces. It is often heavy and hard, and it rings when you hit it. About four out of every five elements are metals, and nearly all of them are solid at room temperature; mercury is the famous liquid one.

Non-metals are much more varied. Many are gases, like the oxygen and nitrogen in the air. The solid ones, like carbon (the grey tip of a pencil) and sulfur, are usually dull, and they crumble or snap instead of bending. Most carry heat and electricity badly.

Here is a common mistake: many people think every metal sticks to a magnet. Only a few do, most of all iron and steel. Aluminium foil, a copper coin, gold and silver don't stick at all.

The periodic table shows the two groups at a glance. Metals fill the left side and the whole middle. Non-metals sit on the right, past a line that runs down like a staircase, plus hydrogen on its own at the top left.

Transcript

1. 0:00Iron, copper, gold. Oxygen, carbon, sulfur. All elements, in two very different groups.
2. 0:07Metals are shiny. They carry heat and electricity. They bend without breaking, and they ring.
3. 0:18Non-metals are different. Many are gases. The solid ones are dull and crumble or snap.
4. 0:26Does every metal stick to a magnet? No. Iron does. Aluminium and copper don't.
5. 0:35In the periodic table, metals fill the left and the middle. Non-metals sit on the right.
6. 0:43Two big groups of elements.