Question

1. where is the energy level the weakest for electrons? *

○ in the nucleus
○ the outer shell
○ in inner shell
○ when the atom becomes an isotope

1. how do you find the number of neutrons in an atom? *

○ electrons - protons
○ atomic mass - atomic number
○ atomic number - protons
○ atomic mass - electrons

1. how many electrons can fit in the first (inner) shell electron shell? *

○ 0
○ 1
○ 2
○ 8

Explanation:

• For Q12: Electrons in the outer shell experience the weakest nuclear attraction, so their energy level is the weakest (easiest to remove).
• For Q10: The number of neutrons is calculated as atomic mass minus atomic number (since atomic mass ≈ protons + neutrons, and atomic number = protons).
• For Q2: The first electron shell follows the $2n^2$ rule where $n=1$, so $2(1)^2=2$ electrons fit.

Answer:

Q12: the outer shell
Q10: atomic mass - atomic number
Q2: 2