Answer: The coefficient of nitrogen in the given equation is 2.
Explanation: The reaction for the oxidation of methamphentamine with oxygen gas in the body is given by:

By Stoichiometry,
4 moles of methamphentamine reacts with 55 moles of oxygen gas to produce 40 moles of carbon dioxide gas, 30 moles of water and 2 moles of nitrogen gas.
Coefficient of 
Coefficient of 
Coefficient of 
Coefficient of 
Coefficient of 
Hence, the coefficient of nitrogen in the given equation is 2.
Answer:
C.
Explanation:
The electronic configuration of N (7 electrons): 1s² 2s² 2p³.
The orbital 1s is filled with two electrons and their spinning direction is opposite and also electrons of 2s.
3p contains (3 electrons) should fill the 3 orbitals firstly. Every orbital contains 1 electron and be in the same spin direction.
So, the right choice is c.
A is wrong because 2 electrons of 3p are paired in the first orbital before filling every orbital.
B is wrong because the 2 electrons of 1s and 2s are in the same direction and also 2 electrons of 3p are paired in the first orbital before filling every orbital.
D is also wrong the 2 electrons of 1s and 2s are in the same direction and the electron in the second orbital of 3p are in opposite direction of the other 2 electrons.
KOH -------> K+ OH-
Ba(OH)2 ------> Ba+2. 2OH-
CLOUDS would be one of the interacting parts in a weather system.