Which. option is an example of physical property

a. density

b. reactivity

c. toxicity

d. flammability

The correct answer is A. Density

Explanation:

In chemistry, a physical property differs from a chemical property because physical properties can be observed or determined without changing the substance. Example of this includes color, density or texture while examples of chemical properties include toxicity, flammability, reactivity, oxidation, etc. Density (mass per unit) is classified as part of physical properties because this can be determined by dividing the mass of the substance by its volume which means this property can be measured without altering the substance and therefore it is a physical property.

1. a)c-14 has two more protons

2. d)they have different numbers of protons, neutrons, and valence electrons; they are all gases at room temperature.

3. c) iron and nickel.