Question

Atoms with the same number of protons but different numbers of neutrons are called ________.

a. isotopes.
b. ions.
c. chemical elements.
d. subatomic particles.

Answer 1

a.isotopes

Ions: atoms of the same element but different number of electrons
Subatomic particles: are what makes up the atom(eg protons,neutrons and electrons)
Chemical elements: Are the elements you see in the periodic table

Answer 2

A. Isotopes

Step-by-step explanation:

Let us look at the definition of each of the terms mentioned before answering the question.

Isotopes - An isotope of a chemical element is an atom that has a different number of neutrons (that is, a greater or lesser atomic mass) than the standard for that element. The atomic number is the number of protons in an atom's nucleus.

Ions - An ion is an atom or molecule that has a net electrical charge.

Chemical element - A chemical element is a species of atom having the same number of protons in their atomic nuclei (that is, the same atomic number, or Z). For example, the atomic number of oxygen is 8, so the element oxygen describes all atoms which have 8 protons.

Sub atomic Particles - subatomic particles are particles that are smaller than atoms. These may be composite particles, such as the neutron and proton.

Among the definitions, we can tell that only isotopes have atoms with same number of protons but different number of neutrons.