Question

Which of the following statements describes a difference between a chemical change and a physical change in a substance

Answer 1

The result of a chemical change is a different composition and is often hard to reverse; in a physical change, the composition remains the same and is often easy to reverse.

Step-by-step explanation:

Answer 2

Step-by-step explanation:

A physical change is one that alters the physical properties of matter (particularly the form and state).

A chemical change is one in which new kind of matter is formed. It is always accompanied by energy changes (evolution or absorption of energy in form of heat or light or both).

Now, the salient differences between physical and chemical changes;

1. Physical changes are easily reversible whereas chemical changes are not easily reversible.
2. Physical changes lead to the production of no new kinds of matter whereas chemical changes leads to the production of new kinds of matter.
3. Physical changes involves no change in mass whereas chemical changes involves change in mass.
4. Physical changes require little energy whereas considerable amount of energy is needed for chemical changes.