Question

Determine whether the following statements describe chemical or physical properties: (a) Oxygen gas supports combustion. (b) Fertilizers help to increase agricultural production. (c) Water boils below 1000C on top of a mountain. (d) Lead is denser than aluminum. (e) Uranium is a radioactive element.

Answer 1

Explanation:

A change that does not cause any change in chemical composition of a substance is known as a physical change.

For example, mass, density, volume etc are all physical changes.

On the other hand, a change that brings change in chemical composition of a substance is known as chemical change.

For example, combustion, toxicity, reactivity etc are all chemical changes.

Hence, following statements are identified as chemical or physical changes as follows.

(a) Oxygen gas supports combustion : Chemical change

(b) Fertilizers help to increase agricultural production : Chemical change

(c) Water boils below $100^{o}C$ on top of a mountain : Physical change

(d) Lead is denser than aluminum : Physical change

(e) Uranium is a radioactive element : Chemical change