Answer:
A.
Explanation:
melting of ice will increase water in oceans due to which water in oceans will increase and salinity will decrease. hence, melting of ice caps near the north pole affects salinity of the ocean
The atmosphere is a mixture of gasses.
Answer:
According to Le-chatelier principle, equilibrium will shift towards left to minimize concentration of 
and keep same equilibrium constant
Explanation:
In this buffer following equilibrium exists -
So, is involved in the above equilibrium.
When a strong base is added to this buffer, then concentration of increases. Hence, according to Le-chatelier principle, above equilibrium will shift towards left to minimize concentration of and keep same equilibrium constant.
Therefore excess amount of combines with 
to produce ammonia and water. So, effect of addition of strong base on pH of buffer gets minimized.
The thing that they have in common is that they are all non metals
