Out of the options, glass is the least fluid. The proof of this also lies in the fact that glass is the most difficult to melt out of all of the mentioned substances, and melting point gives us a rough estimate of the strength of intermolecular forces.
Calcium. This element is in the alkaline earth metals. As such, it <em>could be a good conductor</em>. This is because it can form metallic bonds.
Is there something else that goes along with this?
In here Oxygen is the central atom. It makes two bonds with
Cl and has two lone pairs. Since, the shape is bent and the hybridization is
sp3. Molecular geometry is a bit dissimilar from hybridization. Hybridization
is reliant on the number of bonds and lone pairs. Since O has two bonds with
Cl, its hybridization is sp3. It is like is this: 1 lone pair/bond = s. 2 lone
pairs/bond = sp 3 lone pairs/bonds = sp2, etc. molecular geometry, you count
the number of bonds and lone pairs. This has two bonds and 2 lone pairs so if
they were all bonds, the molecule would be tetrahedral.