Evidence of Physical Changes
- Matter is constantly experience changes
- A physical change occur when the appearance or state of matter changes
- In physical changes, the internal composition of matter remains the same
- E.g. All the changes of state of a substance are physical changes because the particles preserve their identity
Changes of state
Interconversion between states of matter are all physical changes
- Another common example of physical change is the formation or separation of a mixture
- A mixture is a combination between different substances in which the internal structure of its components remain unchanged
- When salt and water are mixed in a beaker, they water molecules and the salt ions interact between them, but their internal structure stays the same
- The mixture can be separated into its components by a simple distillation. Water can be collected in a separate container, while salt will remain the in the round bottomed flask
Separation of a mixture between water and salt
The separation of a mixture is a common physical change because the components do not lose their internal structure