Answer:
Covalent compounds are held by intermolecular forces while network solids are held by strong bonds in unit cells which are closely packed together.
Explanation:
Covalent compound molecules are held by vanderwaals forces which are relatively weak but strong enough to hold some covalent molecules together in the solid state. However, network solids contain atom to atom covalent bonds arranged in an orderly manner and regular repeating unit cells to form a rigid three dimensional network solid.
Answer:

Explanation:
First of all we need to find the amount of atoms per volume (m³). We can do this using the density and the molar mass.

Now, the fraction of vacancies is equal to the N(v)/N ratio.
- N(v) is the number of vacancies

- N is the number of atoms per volume calculated above.
Therefore:
The fraction of vacancies at 600 °C will be:

I hope it helps you!
High tides occur 12 hours and 2 minutes apart do it would be at 6:25 pm
Number of moles = 5.7 moles of oxygen.
<u>Explanation:</u>
We have to convert number of molecules into number of moles by dividing the number of molecules by Avogadro's number.
Here number of molecules of oxygen given is 34.1 × 10²³ molecules.
Now we have to divide the number of molecules by Avogadro's number as,
Number of moles = 
= 
= 5.7 moles
So here molecules is converted into moles.