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Which of the following is a physical change? Which is a chemical change?
1. Heating wax until it melts ( Physical, Chemical, Physical and Chemical )
2. Crush some salt crystals into a powder ( Physical, Chemical, Physical and Chemical )
3. Boiling water until it evaporates, then condensing the
steam. ( Physical, Chemical, Physical and chemical )
4. Boiling an egg in boiling water for two minutes, then
cooling the water. ( Physical, Chemical, physical and chemical )
5. Heating a piece of paper until it turns black, then cooling
it. ( Physical, chemical, physical and chemical )
6. Heating a mixture of hydrogen and oxygen until it
“pops”, and then cooling the gases to a liquid. ( Physical, Chemical, physical and chemical )
7. Dissolving salt into water to make a solution ( Physical, Chemical, physical and chemical )
8. Cooking a steak until it is well done ( Physical, Chemical, physical and chemical )
9. Burning magnesium ribbon in air ( Physical, chemical, physical and chemical )