Physical and Chemical Changes
By Kendall Croswell
A Physical change requires a change in physical properties. Physical changes occur when a substance or object undergoes a change that does not change the chemical composition of the substance or object. Examples of Physical changes are: melting, changes in shape, size,density, and transition to a gas.
A chemical change is any change that results in the formation of a new chemical substance. This includes the making or breaking of bonds between atoms. Some examples of chemical changes are: iron rusting, gas burning, eggs cooking, bread rising, milk souring, and suntanning.