How can YOU tell if the change physical or chemical ?
Production of gas
Production of gas is when what ever you just nixed, makes bubbles. Though if you add heat, it doesn't count as a chemical change, it counts as you boiling a liquid.
When two or more liquids mix and make a different color.
A liquid to a solid
When two or more liquids mix to make a solid
When two liquids mix and change temperature without adding any heat.