Question

Which of the following is an example of a physical change? A) grinding coffee beans B) baking a cake C) converting water to hydrogen and oxygen D) digesting a cheeseburger E) burning coal

Answer 1

Answer: A) grinding coffee beans

Explanation:

A physical change is defined as a change in which there is alteration in shape, size etc. No new substance gets formed in these reactions.

A chemical change is defined as a change in which a change in chemical composition takes place. A new substance is formed in these reactions.

1. Grinding coffee : Only change in size takes place, thus a physical change

2. Baking a cake: the chemical reaction occurs by combination of flour with oxygen , thus a chemical change.

3.:converting water to hydrogen and oxygen: The decomposition iof water takes place, thus is a chemical change

4.Burning of coal: the chemical reaction occurs by combination of carbon with oxygen , thus a chemical change.