D) refracted
because , the light changes direction.. causing the penny to look bigger than it is.
Answer: 69.72 kg of cryolite will be produced.
Explanation:
The balanced chemical equation is:
To calculate the moles, we use the equation:
moles of 
= 
moles of 
= 
moles of 
= 
As 1 mole of reacts with 6 moles of
166 moles of reacts with = 
moles of
As 1 mole of reacts with 12 moles of
166 moles of reacts with = 
moles of
Thus is the limiting reagent.
As 1 mole of produces = 2 moles of cryolite
166 moles of reacts with = 
moles of cryolite
Mass of cryolite 
= 
Thus 69.72 kg of cryolite will be produced.
The correct option is D.
The hydrogen atoms that are attached to the nitrogen atom in the ammonia molecule are capable of forming hydrogen bond. The hydrogen bond that exist in the ammonia molecule is the reason why it shows higher boiling point compare to the other hydrides. Hydrogen bond occur in ammonia because ammonia is one of the most electronegative elements.
Nitrogen can make bonds with other atoms.. Typically though it only makes 3 bonds, so it fills its octet.
