I can't see the pictures clearly but maybe this will help
Here are the resonance contributors I found.
You would think that the bag of nails would have more mass but their masses are identical. <span>If you were to put them both in a vacuum chamber and let them fall from a great height, they would fall the same speed. The vacuum chamber would suck all of the air out of the cotton balls, thus making it heavier and weigh the same as the bag of nails.
Hopefully this is helpful and makes sense.</span>
When you calculate the first two numbers in 493×10
They have different number of Neutrons and protons, so their masses are different
Hope this helps!
