Reversible and irreversible changes

Worksheet: Reversible and irreversible changes

Name:Class:

Answer the questions.

1. When sugar mixes into water and seems to disappear, what have you made?
   a) A gasb) A metalc) A solidd) A solution
2. In a salt solution, which word describes the salt?
   a) Filterb) Residuec) Soluted) Solvent
3. Sand dissolves in water to make a solution.
   a) Trueb) False
4. Which change is reversible?
   a) Baking a cakeb) Burning paperc) Melting iced) Rusting a nail
5. Chocolate melts in the sun. What can you do to make it solid again?
   a) Burn itb) Cool itc) Heat it mored) Stir it in water
6. What is the name for water turning into ice?
7. Which change is irreversible?
   a) Dissolving salt in waterb) Freezing waterc) Frying an eggd) Melting butter
8. An iron nail left in wet air turns orange-brown. What is this called?
   a) Dissolvingb) Freezingc) Meltingd) Rusting
9. Once wood has burned to ash, we cannot change it back into wood.
   a) Trueb) False
10. Which tool best separates large stones from fine sand?
    a) A magnetb) A sievec) A spoond) A thermometer
11. Muddy water is poured through filter paper. What stays on the paper?
    a) All the waterb) Dissolved saltc) Nothing at alld) The solid mud
12. What word describes a material, like sand, that cannot dissolve in water?
13. How can you get salt back from salty water?
    a) Evaporate the waterb) Filter itc) Freeze it onlyd) Sieve it
14. Filtering can separate dissolved salt from water.
    a) Trueb) False
15. To separate sand and salt, which liquid do you add to dissolve the salt?
16. Why can't a baked cake turn back into runny cake mixture?
    a) Heat made new materialsb) It dissolved in airc) It was filteredd) It was only melted