Johnny was brave because he went back into the building for the children.
A.
Explanation:
There are several reasons that Carbon-12 was chosen as the standard for determining the relative mass of other atoms.
- Its abundance on earth
- Carbon-12 is a very stable isotope atom
- Its has the same number of neutrons and protons hence more ideal to use for a precise calculation of <em>amu</em> (atomic mass unit) -
The mass of an atom are based on the ¹/12 mass of Carbon-12.
I would say A because they are comparing very real books to a dramatization of said "witch trials"
