A notation that shows which elements, and how many of each type a compound contains is a(an) .
a. Chemical formula c. Molecule
b. Anion d. Polar Covalent Bond

a. Chemical formula

Explanation:

A notation that shows which elements, and how many of each type a compound contains is a chemical formula.

Basically, a chemical formula helps scientists to show or illustrate the type and number of atoms present in a particular molecule or compound by using numerical subscript, ions and atomic symbol of a chemical element.

This ultimately implies that, a chemical formula is used to describe or denote the exact amount of atoms that make up a molecule or compound.

Some examples of a chemical formula are;

Water =

Sodium Hydroxide =

Hydrochloric acid =

Carbon II oxide =

what is the speed of a softball that travels 20m in 2secs

speed = 20/2 = 10 m/s