Lithium atomic mass number

 

Question: 28 of 44

CORRECT

• Time Remaining: 07:27:01

An atom of lithium has 3 protons, 4 neutrons, and 3 electrons. What is this atom's mass number?

3

This is the atomic number of the atom, not the atom's mass number. The atomic number is the number of protons in an atom.

6

This is the sum of protons and electrons in this atom, which does not produce the atom's mass number.

10

This is the sum of protons, neutrons, and electrons, which does not produce the atom's mass number.

7

MY ANSWER

The mass number of an atom is the sum of the number of protons and neutrons in its nucleus.