Question

Reversible name 1 that is useful

Answer 1

shape and size of rubber band

Answer 2

Reversible change or physical change are those changes in which substances undergoes chahe in physical state.

The most common and useful physical change is :

Conversion of water in vapour and vapour to rain.

This change helps in regulation of Hydrological cycle, which brings back the rainfall on earth.

This continues as,
Evaporation => Condensation => Precipitation.

All in this water is involved in some how in differnt states of matter.