Answer:
- A new substance was formed in the chemical change while no be substance was formed in the physical change
- The chemical change involved a change in chemical composition while the physical change involved no change in chemical composition
Please find the explanation below.
Explanation:
A physical change is a change that does not alter the chemical content of the substances involved, hence, no new substances are produced while a chemical change alters the chemical composition, hence, new substances results.
In this question,
- Water is heated till it forms steam is characterized as a physical change
- Lighted splint is applied to hydrogen gas to produce water in the form of steam is characterized as a chemical change.
- The first process is a PHYSICAL CHANGE because it involved only a change of state i.e. from liquid to gas, hence, no alteration to the chemical composition of the molecule and also no new substance is produced.
- The second process is a CHEMICAL CHANGE because there was a chemical combination of hydrogen gas and the oxygen in the lighted splint to yield water molecules ( a new substance). Therefore, it involved a chemical reaction and formation of a new substance
