Is expansion a physical or chemical property?

Answer 1

While a chemical change in an object can lead to its expansion, Take a piece of iron rusting for example, the same piece of iron could expand as a result of it being heated. So it would be reasonable to say neither. expansion is an increase of volume or area being taken up .

Answer 2

Expansion of metals due to heating (as referenced by coefficient of expansion) is a physical change.

Expansion of metals as a phase change (e.g. from alpha to delta-phase plutonium) is likewise a physical change. This is due to different ordering of atoms in the lattice, not just increase in distance due to higher energy in the bonds between them.

Expansion of metals due to void swelling is a physical change.

You'll have to make a semantic decision about something like alpha-particle absorption, where the alpha will take up two electrons from the metal and convert to helium. I consider this a physical change, a bit like ionization in reverse.

Any chemical change that affects 'expansion' -- in particular, through corrosion inclusions -- does not leave the original metal unaffected. (The inclusions will be oxides, chlorides, etc., with very different physical and mechanical properties). While a metal part or component may change shape and size, and this will almost always be an expansion due to the addition of atoms in combination with the metal's, I don't think this is what the original question was asking about. I invite the original questioner to add to or clarify what they mean by 'expansion of metals' if the above isn't clear enough.

Answer 3

If matter expands, it is typically considered a physical change. It did not change chemically. It merely changed in size.

Answer 4

Expansion is a physical property.

Answer 5

physical change;)