The metal elements
About three-quarters of all elements are metals. They are found on the left side and in the middle of the periodic table. Metals have shaped human history so much that archaeologists name whole eras after them: the Bronze Age and the Iron Age.
Properties of metals
| Property | What it means | Example |
|---|---|---|
| Lustre | Shiny when polished | Silver, gold |
| Conductor of heat | Heat flows through easily | Pots and pans |
| Conductor of electricity | Electricity flows through easily | Copper wires |
| Malleable | Can be hammered into sheets | Aluminum foil; gold leaf can be beaten thinner than a hair |
| Ductile | Can be stretched into wires | Copper wire |
| Strong | Resist breaking | Steel beams |
| High density | Usually heavy for their size | Lead |
| High melting point | Most are solids at room temperature | Iron melts at 1538 °C |
| Sonorous | Ring when struck | Bells |
Exceptions: mercury is a liquid at room temperature, and sodium is so soft you can cut it with a knife.
Why metals behave this way
Metal atoms give up their outer electrons into a shared "sea" of electrons that moves freely around the positive metal ions. This metallic bonding explains the properties:
- Free-moving electrons carry electricity and heat.
- Layers of ions can slide past each other without breaking the bonds, so metals bend instead of shattering.
- Free electrons reflect light, making metals shiny.
Families of metals
| Group | Examples | Notes |
|---|---|---|
| Alkali metals (group 1) | Lithium, sodium, potassium | Very reactive; react with water, sometimes explosively; stored in oil |
| Alkaline earth metals (group 2) | Magnesium, calcium | Reactive; calcium is in bones |
| Transition metals | Iron, copper, gold, silver, nickel | Strong, often colourful compounds; used in construction and jewellery |
| Other metals | Aluminum, tin, lead | Softer; many uses |
| Lanthanides and actinides | Neodymium, uranium | Magnets, electronics, nuclear fuel |
Reactivity
Metals react with oxygen, water and acids at different rates.
Most reactive → least reactive: potassium, sodium, calcium, magnesium, aluminum, zinc, iron, lead, copper, silver, gold
Gold is so unreactive that it’s found as pure nuggets and stays shiny for thousands of years. That’s why ancient gold treasures still gleam.
Corrosion
Corrosion is the slow breakdown of a metal by chemical reactions with its surroundings.
- Iron + oxygen + water → rust (iron oxide). Rust flakes off, exposing more iron.
- Copper turns green when it reacts with air over many years. The copper roofs of Canada’s Parliament buildings are green for this reason.
- Aluminum forms a thin oxide layer that actually protects it from further corrosion.
Ways to prevent rust: paint, oil, plastic coatings, and galvanizing (coating steel with zinc).
Alloys
An alloy is a mixture of a metal with other elements. Alloys are often stronger or more useful than pure metals.
| Alloy | Made from | Uses |
|---|---|---|
| Steel | Iron + carbon | Buildings, cars, tools |
| Stainless steel | Iron + chromium + nickel | Cutlery, sinks; resists rust |
| Bronze | Copper + tin | Statues, medals, bells |
| Brass | Copper + zinc | Musical instruments, door handles |
| Solder | Tin + other metals | Joining electronic parts |
| 14-karat gold | Gold + silver, copper | Jewellery (pure gold is too soft) |
Getting metals from the ground
Most metals are found in rocks called ores, combined with other elements.
- Mining digs ore from the ground.
- The ore is crushed and concentrated.
- Smelting heats the ore, often with carbon, to release the metal. Iron is smelted in blast furnaces.
- Some metals, like aluminum, are extracted using electricity.
Canada is one of the world’s top producers of nickel, aluminum, potash, uranium and gold. Sudbury, Ontario, is famous for its nickel mines, located in a basin thought to have been formed by a giant meteorite impact 1.85 billion years ago.
Recycling metals
Metals can be recycled again and again without losing quality. Recycling aluminum uses about 95% less energy than making it from ore.
Common mistakes
- Thinking all metals are magnetic. Only a few, like iron, nickel and cobalt, are.
- Thinking all metals are solid. Mercury is a liquid.
- Thinking rust is just dirt. It’s a new chemical compound.
Try it yourself
- Test metal objects for magnetism, then sort them.
- Put iron nails in three test tubes: dry air, tap water, and salt water. Check for rust over a week.
- Feel a metal spoon and a wooden spoon in a cold room. Which feels colder? Why?
Quick recap
- Metals are shiny, conduct heat and electricity, and are malleable and ductile.
- Metallic bonding with a sea of electrons explains these properties.
- Metals vary in reactivity; gold is very unreactive.
- Alloys like steel and bronze improve metal properties.
- Metals are extracted from ores and can be recycled.