Which of the following changes are chemical changes?
a. water is frozen.
b. water is heated up.
c. gasoline is burned.
d. gasoline is evaporated.
e. water is boiled.

Option (c) is the correct answer.

Explanation:

A change that does not bring any difference in chemical composition of a substance are known as physical properties.

For example, shape, size, mass, volume, density, etc of a substance are all physical change.

And, a change in which there occurs a difference in chemical composition of a substance then it is known as chemical change.

For example, precipitation, reactivity, toxicity etc are chemical change.

When gasoline is burned then it is a chemical change.

Thus, we can conclude that out of the given options gasoline is burned change is a chemical change.

frequency, z, and the collision density, z, in carbon dioxide (co2), r 180 pm at 30 °c and 120 kpa