Answer:
1) rusting of metal is both chemical and physical change
2) black ice is an example of a physical change
Explanation:
when metal rusts, it is due to a reaction between the atoms in the metal and the atoms in the air(oxygen) or water(oxygen). When it rusts it also physically changes the look of the metal from silver to dirty brownish maroon.
Black ice is a change in state hence it cannot be a chemical change as the original substance NO LONGER EXISTS in a chemical reaction. It is a physical change however as the ice is changing into a different state of matter.
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