Explanation:
Since, the atomic number of nitrogen is 7 and its electronic distribution is 2, 5. So, in order to attain stability it needs to gain 3 electrons.
Hence, when it chemically combines another nitrogen atom then as both the atoms are non-metals. So, sharing of electrons will take place.
Also, there is no difference in electronegativity of two nitrogen atoms. Hence, compound formed 
is non-polar covalent in nature.
This question is very unspecific, but it is probably the Mantle. If that is wrong try Crust.<span />
Answer:
the mass number is the number of protons and neutrons added and the average atomic mass is the weight of the protons and neutrons
Answer:
C. Water passes into the salt solution, dehydrating bacterial cells and making them harmless.
Explanation:
The salt solution is hypertonic to the bacterial cells and as such, water molecules will move from the bacterial cells into the salt solution, dehydrating the cells and rendering them harmless.
Option A is also true but it is irrelevant to the question asked. Option B and D are wrong.
The correct option is C.
