Calcium chloride forms an ionic compound with a
regularly arranged lattice of oppositely charged ions.
The Na+ and Cl- ions are held together by
strong electrostatic forces.
Hope that helps
the poly atomic molecule is H2
Answer: 13.9 g of
will be produced from the given mass of oxygen
Explanation:
To calculate the moles :

The balanced chemical reaction is:
According to stoichiometry :
7 moles of
produce = 6 moles of 
Thus 0.900 moles of
will produce =
of 
Mass of 
Thus 13.9 g of
will be produced from the given mass of oxygen
Answer: The correct option is A.
Explanation: The given molecules are the molecules of same element.
These molecules are considered as diatomic species.
Polar molecules are the molecules in which some polarity is present in the bond. These molecules are formed when there is some difference in the electronegativities of the elements. Example: HCl
Non-polar molecules are the molecules where no polarity is present in the bond. These molecules are formed when there is no difference in the electronegativities of the elements. Example: 
The given molecules are non-polar in nature.
Hence, these molecules must be non-polar. So, the correct option is A.