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Tiny pieces

Radiation and the atom · level 1, lesson 1 of 6

A question to start

A sandcastle looks like one big lump. Is it, really?

The idea

Look closely at sand and you see it is made of tiny grains. Look at a grain of sand with a magnifying glass, and it looks like a little rock.

Scientists have found that everything is made of tiny pieces, even things that look smooth, like water, glass and your skin. Those pieces are much, much smaller than sand grains, far too small to see even with a magnifying glass.

  • A sandcastle is made of grains of sand.
  • A grain of sand is made of pieces far smaller still.
  • So is the air, the water and you.
a sandcastleup close: tiny grains

Worked examples

1. Sugar. A spoonful of sugar is made of little crystals. Look closely and you can see their shiny sides.

2. Flour. Flour feels smooth, but it is made of grains, just much smaller than sugar.

3. Water. Water looks smooth all the way through. Its pieces are so small that no magnifying glass can show them.

Try it

  1. What is a sandcastle made of?
  2. Name something that looks smooth but is made of tiny pieces.
  3. Which has smaller grains: sugar or flour?
  4. Can you see the tiny pieces that water is made of?
Answers
  1. Tiny grains of sand.
  2. Any one: water, glass, flour, your skin, the air.
  3. Flour.
  4. No, they are far too small, even with a magnifying glass.

Common mistake

"Smooth things are not made of pieces." Everything is made of pieces. In smooth things, the pieces are just far too small to see.

Where it leads