Answer
3 electrons
Work Step by Step
Although the ⁶Li and ⁷Li isotopes have different mass numbers, the Li atom is defined by the number of protons it contains in its nucleus, which is 3. To balance the charge of these protons, 3 electrons orbit to make the atom neutral.
The difference between the ⁶Li and ⁷Li isotopes is the number of neutrons in their nuclei. ⁶Li contains 3 and ⁷Li contains 4. However, since neutrons do not carry a charge, they do not influence whether an atom is neutral or not.
