Why evaporation of water a physical change and not chemical?

Answer 1

Water in solid form, as ice, is chemically H2O

In liquid form it is also only H2O

In gas form, as water vapour, it is still only H2O, albeit that the molecules/atoms have greater activity and that the volume is much greater than that of water in the liquid state.

Answer 2

Unlike a chemical change, evaporation does not change the arrangement of atoms, it just adds energy to them. An example of a chemical change would be electrolysis, which separates water into Hydrogen and Oxygen.

Answer 3

The definition of a chemical change is a change in the chemical nature of a substance. In other words, a new substance is created. Water(H2O) evaporates and becomes steam. It is a physical change because the steam is simply a different form of H2O.

Answer 4

Water molecules, no matter their form (solid, liquid gaseous) have the chemical formula H2O. This chemical formula and the arangement of the atoms in the molecule (tetrahedral) never changes. So there we call that no chemical change. However, as the temperature of water molecules change, we notice a change in the physical characteristics of the molecule (eventhough the molecule is chemically the same old water molecule).

Answer 5

Nothing is chemically changed when water goes from liquid-->gas. All that's happening is the molecules moving faster.

H20(l)-->H20(g)

Answer 6

Because its non- flammable and it is reactive

Answer 7

When water is a puddle on the table, it is H2O.

When it evaporates into the air, it is still H2O.

The change is physical, not chemical.

Answer 8

Evaporation is a physical change because the substance evaporating does not undergo a change in chemical composition.

Answer 9

Evaporation doesn't involve a chemical process, a change of the molecule.