Question 5
What sits at the lattice points of an atomic lattice, and what holds them there?
The right answer is the one marked above.
Atoms held to one another by covalent bonds. That is exactly what distinguishes an atomic lattice from an ionic one.
Ions held by electrostatic attraction describes an ionic lattice, such as sodium chloride. Weakly attracting molecules describe an ordinary covalent solid, which is why those melt at low temperatures.