Understanding Physical and Chemical Changes in Matter

A chemical change is when substances are changed into different substances with a new chemical composition. Physical change involves a change in the physical state or appearance of a substance without altering its chemical composition. Nuclear change refers to changes in the nucleus of atoms, whereas mechanical change involves physical forces causing changes in shape or form.

The burning of wood involves a chemical reaction where the wood reacts with oxygen to produce heat, light, and new chemical compounds. This process is irreversible and results in the formation of different substances, making it a chemical change.

Burning wood involves a chemical reaction where the wood undergoes a combustion process, resulting in the formation of new substances like ash and smoke. This irreversible change is a clear example of a chemical change.

Freezing of water is a physical change because it involves a change in state from liquid to solid without altering the chemical composition of water molecules.

Freezing water is a physical change because it involves a change in state from liquid to solid without altering the chemical composition of water molecules. No new substances are formed in this process.

Cutting a piece of paper is a physical change because it does not alter the chemical composition of the paper, only its physical state.

A physical change is a type of change in which the form or appearance of matter changes, but its composition remains the same. Other options like chemical change involve a change in composition, phase change involves a change in state, and biological change involves changes in living organisms.