Which of these processes indicates that smelting copper is a chemical change?

The diagram shows the positions of the sun, moon and earth during spring tides, when the high tides are at their highest and low tides at their lowest. what is it about these positions that causes these high and low tides?

How do i complete this electrolysis of water lab? i’m at home, so i don’t have the materials, and the lab didn’t properly work and was incomplete at school.

If i can still dissolve more sugar into the solution at a certain temperature what would i call that solution