Question

which numbers/symbols correctly complete the table above?
li, 3, 3
li, 6, 3
li, 6, 2
li, 3, 2

Explanation:

Step1: Determine the element

The element with atomic number 3 is Lithium (Li).

Step2: Calculate the mass number

Mass number = Protons + Neutrons. Given protons = 3 and neutrons = 3, mass number = 3 + 3 = 6.

Step3: Determine the electron configuration

For a neutral atom, electrons = protons = 3. But since the charge is +1, electrons = 3 - 1 = 2. The electron configuration for Li⁺: 1st shell (K - shell) can hold 2 electrons. So it is 2 electrons in the first shell.

Answer:

Li, 6, 3, 3, 2, +1