The main reason to use a visual aid in a presentation is to ensure concepts are more challenging to understand.
make a challenging concept easier to understand.
guarantee that complex information is accurate.
keep an audience’s attention through distraction.

Hope the image of the frequency formula

The atomic nucleus made up from protons (yellow) and neutrons (blue) and held together by nuclear forces. nuclear forces (also known as nuclear interactions or strong forces) are the forces that act between two or more nucleons. they bind protons and neutrons (“nucleons”) into atomic

The answer to your q the total mass is 73