1. a change of matter (substance) from one form to another without a change inchemical properties

So,

There are two basic types of changes in chemistry: physical changes and chemical changes.

Physical changes do not change the chemical identity of the substance; instead physical changes operate between molecules/atoms/ions/etc.  Changes of phase and separation of different substances in a mixture are examples of physical changes.  For example, when you change the phase of liquid water to gas, you are operating between the water molecules by breaking the intermolecular attractions.  Yet you still have water, H2O.  When you separate iron filings from a mixture of sand and iron filings with a magnet, you are, in a way, operating between the atoms of iron.  Yet you still have iron and sand.

Chemical changes change the chemical identity of the substance.  When you throw salt into water, the salt dissolves and is no longer salt.  You get salt water, which is chemically different from water and salt.  You have operated inside the salt compound.

Thus, changing matter from one form to another without a change in chemical properties would be a physical change.