Question

a certain atom has 20 electrons, 20 neutrons, and 20 protons. what is the atomic mass of the atom? a 21 b 40 c 61 d 20

Explanation:

Step1: Recall the formula for atomic mass

Atomic mass \(=\) number of protons \(+\) number of neutrons.

Step2: Substitute the given values

Given that the number of protons \(= 20\) and the number of neutrons \(= 20\). Then atomic mass \(=20 + 20\).

Step3: Calculate the result

\(20+20=40\).

Answer:

B. 40