Question

Which would show an example of how physical changes are reversible?

cutting a gold bar in two pieces and then putting the pieces next to each other
burning a match and then relighting it
melting tin and then cooling it into a mold
combining sodium and chlorine to make the new material of table salt

Answer 1

C

Step-by-step explanation:

the physical change was the gold bar being cut and if it is put back together the physical change is reversed

Answer 2

Melting tin and then cooling it into a mold

Step-by-step explanation:

When you melt something, and when it cools it returns to its physical state, therefore the physical changes are reversible. For example, take chocolate. When chocolate melts its liquid, then when it's in a colder situation it becomes solid again and so on, the changes are reversible.