Which statement best describes chemical properties of matter?
a)chemical properties, such as density, must be observed when a substance is in its natural state at room temperature and normal atmospheric pressure.
b)chemical properties, such as reactivity, must be observed when a substance is in its natural state at room temperature and normal atmospheric pressure.
c)chemical properties, such as combustibility, are generally observed as the identity of a substance changes and one or more new substances form.
d)chemical properties, such as boiling point, are generally observed as the identity of a substance changes and one or more new substances form.

Option (C) is the correct answer.

Explanation:

A property that changes chemical composition of a substance is known as chemical property.

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

A chemical property or reaction will always lead to the formation of a new product.

So, chemical properties such as combustibility, are generally observed as the identity of a substance changes and one or more new substances form.

On the other hand, a property that does not bring any change 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 properties.

Thus, we can conclude that the statement chemical properties, such as combustibility, are generally observed as the identity of a substance changes and one or more new substances form, best describes chemical properties of matter.

c. electrical charges of ionic bonds.