Chemical and Physical Changes

precipitate

a solid that forms during a chemical reaction between two liquids. This is a sign of a chemical change.

production of a gas

A release of a new substance in the form of a gas not originally present in the solution. This is a sign of a chemical change.

chemical property

A property of a substance that can only be tested by changing the identity of the substance.

production of light

Light energy can be produced by a chemical reaction. This is a sign of a chemical change.

temperature change

A chemical reaction may absorb or release heat causing the temperature to rise or fall. This is a sign of a chemical change.

color change

A chemical reaction may create a new substance which displays a new color that was not originally part of the solution. This is a sign of a chemical change.

physical property

property of matter that does not change a substance when observed. Observed using at least 1 of the 5 senses.

physical change

change in matter that does not result in a new substance. This type of change can usually be reversed.

chemical reaction

reaction involving changes that result in at least one new substance being created. Reactants react to produce products.

chemical change

change in matter as a result of a reaction which results in at least one new substance. This type of change is typically difficult to reverse.

evidence

data collected from observations and experiments

phase change

a change from one state (solid or liquid or gas) to another; this is a physical change

phases of matter

solid, liquid, gas & plasma

rust

happens because iron combines with oxygen in the atmosphere. Chemical bonds are created and destroyed to finally make iron oxide. This is evidence of a chemical change.

tarnish

discoloration of metal surface caused by oxidation. This is evidence of a chemical change.