Question

1. what is the main difference between physical and chemical change? (p. 3 - 4)

Explanation:

A physical change is a change in which no new substances are formed. For example, melting ice (solid water) to get liquid water. The chemical composition of water (\(H_2O\)) remains the same. A chemical change is a change in which new substances are formed. For example, burning wood. Wood (a complex organic compound) reacts with oxygen (\(O_2\)) to form carbon - dioxide (\(CO_2\)), water (\(H_2O\)) and ash (new substances).

Answer:

The main difference is that in a physical change, no new substances are formed, while in a chemical change, new substances are formed.