Question

how many electrons does a neutral $^{40}$ca atom contain?
periodictable.pdf
○ a. 20
○ b. 18
○ c. 22
○ d. 40

Explanation:

Step1: Find Ca's atomic number

Calcium (Ca) has an atomic number of 20, meaning it has 20 protons.

Step2: Neutral atom electron-proton equality

In a neutral atom, number of electrons = number of protons.
So, electrons = 20.

Answer:

a. 20