2. Atoms and the Periodic Table

Potassium consists of three isotopes, ${}_{19}^{39}\text{K}$, ${}_{19}^{40}\text{K}$, and ${}_{19}^{41}\text{K}$. Based on its atomic mass, which isotope of potassium is the most abundant?

Vanadium consists of two isotopes, ${}_{23}^{50}\text{V}$ and ${}_{23}^{51}\text{V}$ . If the atomic mass for copper on the periodic table is 50.942 amu, are there more atoms of ${}_{23}^{50}\text{V}$ and ${}_{23}^{51}\text{V}$ in a sample of vanadium?

Which of the following choices has the greatest atomic mass?