Looking at what things are made of and why
Everything around us is made of materials. A table may be made of wood, a spoon of steel, a bottle of plastic or glass, and a shirt of cotton. We can sort materials by what they look and feel like: some are hard like stone, others soft like cotton wool; some are shiny like metals, others dull like wood; some are rough and some are smooth.
Some materials let light pass through, like glass windows, while others block it, like wooden doors. Some, like sugar and salt, dissolve in water, while sand and chalk do not. Some float, such as wood and cork, and some sink, such as iron and stone. Materials come from nature, like wood, cotton and clay, or are made by people, like plastic and nylon. We choose a material because of its properties: an umbrella is made of waterproof cloth, and cooking pots are made of metal because metal lets heat pass through easily.
Why it matters
Choosing the right material keeps us safe and comfortable, from rubber soles that do not slip to glass that lets light into our homes. Knowing which materials can be reused or recycled, such as paper and glass, helps reduce waste. Sorting materials by their properties is the first step towards chemistry topics like solids, liquids and gases.
Key terms
- Material
- The substance an object is made from, such as wood, metal or plastic.
- Waterproof
- Describes a material that does not let water pass through it.
- Natural material
- A material that comes from plants, animals or the ground, such as cotton or clay.