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Which substance can dissolve completely in water?
Substances that dissolve in water are called
How could you separate a mixture of sand and salt?
Mix with water, filter, and then evaporate
Mix with water, evaporate and then filter
Filter and then mix with water
Will the steam from seawater be salty?
Some of the steam will be salty
Are melting, freezing, boiling, evaporating and condensing ALWAYS reversible changes?
Which of these is a reversible change?
Baking a cake
Freezing orange juice to make an ice lolly
Which of these is an irreversible change?
Candle wax melting
Candle wax burning
Ice cream melting
What new materials are formed when a candle burns?
Water and carbon dioxide and soot
No new materials are formed
How could you change burnt paper back into its original form?
Scrape off the soot
Which of these statements is FALSE?
Freezing is not a reversible change
Heating a substance can cause both reversible and irreversible changes
Dissolving is a reversible change