Every Substance Melts at Its Own Temperature
- Chemistry
- Ages 8–11 · Grades 3–5
- Hands-on experiment
What you’ll find out
- Temperature is measured with a thermometer, in degrees Celsius.
- Pure water freezes at 0 °C and boils at 100 °C near sea level.
- Each substance melts at its own temperature, which helps identify it.
No sign-up and no real names. In the lesson you check your understanding as you read, run the experiment yourself, and practise until it sticks.
Measuring hot and cold
You can feel hot and cold, but your skin can be fooled. Put one hand in cold water and one hand in hot water. Then put both in lukewarm water. It feels warm to one hand and cool to the other! A thermometer gives a number instead. Scientists use degrees Celsius, written °C. Pure water freezes at 0 °C. It boils at 100 °C. Your body is about 37 °C. A warm bath is about 40 °C.
Melting points are clues
Every substance melts at its own temperature. This is called its melting point. Ice melts at 0 °C. Chocolate starts to melt at about 34 °C. That is just below the temperature of your body, so it melts in your mouth. Candle wax melts at about 60 °C. Salt must be heated to about 800 °C before it melts! Because each substance melts at its own temperature, the melting point is a clue to what it is. Salt also makes ice melt, even when it is colder than 0 °C. That is why salt is put on icy roads.
Curriculum links: NGSS 5-PS1-3