Question

Which statement accurately defines the mass number of an element?

a. The number of electrons in the element.

b. The number of protons in the element.

c. The number of protons plus neutrons in the element.

d. The number of protons plus electrons in the element

Answer 1

The mass number of an element is the total number of protons plus neutrons in the nucleus of an atom, not to be confused with the atomic number which is only the number of protons. (Option C).

Step-by-step explanation:

Which statement accurately defines the mass number of an element?

The correct answer is c.

The mass number of an element is defined as the number of protons plus neutrons in the nucleus of an atom. This is not to be confused with the atomic number, which is solely the number of protons and determines the element's identity.

The mass number (A) is important as it contributes to the atom's mass along with the protons.

For example, if you have a carbon atom, which by definition has 6 protons (its atomic number), and it also has 6 neutrons, then its mass number would be 6 protons + 6 neutrons = 12.

Therefore, the mass number can be calculated using the formula: Mass number = atomic number (Z) + number of neutrons.