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.
I have heard they can use hair is stocking or nets to absorb the oil out of the water
False, pepsin and hydrochloric acid

☃️ Chemical formulae ➝ 
How to find?
For solving this question, We need to know how to find moles of solution or any substance if a certain weight is given.

Solution:
❍ Molecular weight of 
= 2 × 126.90
= 253.80
= 254 (approx.)
❍ Given weight: 12.7
Then, no. of moles,
⇛ No. of moles = 12.7 / 254
⇛ No. of moles = 0.05 moles
⚘ No. of moles of Iodine molecule in the given weight = <u>0.05</u><u> </u><u>moles </u>
<u>━━━━━━━━━━━━━━━━━━━━</u>
Answer :
(a) displacement reaction
(b) combination reaction
(c) disproportionation reaction
(d) displacement reaction
Explanation :
(a) The given balanced chemical reaction is,

This reaction is a single replacement reaction or displacement in which the the more reactive element (Fe) replace the less reactive element (H).
(b) The given balanced chemical reaction is,

This reaction is a combination reaction in which the two reactants molecule combine to form a large molecule or single product.
(c) The given balanced chemical reaction is,

This reaction is a disproportionation reaction in which the chemical species gets oxidized and reduced simultaneously. It is also considered as a redox reaction.
(d) The given balanced chemical reaction is,

This reaction is a single replacement reaction or displacement in which the the more reactive element (Ag) replace the less reactive element (Pt).