Which of the following are physical properties?
1. Water freezes at 0°C.
2. Diamonds are the hardest known substance.
3. Sugar is capable of dissolving in water.
4. Vinegar reacts with baking soda.
5. Most metals are malleable.
6. Most metals react with acids.
7. The density of acetic acid is 1.05 g/mL.
8. The length of a piece of aluminum foil is 12.2 cm.
9. Copper conducts electricity.