It's A
a. the electron configuration of a noble gas.
Answer: Melatonin has been used safely for up to 2 years in some people. However, it can cause some side effects including headache, short-term feelings of depression, daytime sleepiness, dizziness, stomach cramps, and irritability. Do not drive or use machinery for four to five hours after taking melatonin.
Answer : The oxidizing element is N and reducing element is O.
is act as an oxidizing agent as well as reducing agent.
Explanation :
An Oxidizing agent is the agent which has ability to oxidize other or a higher in oxidation number.
Reducing agent is the agent which has ability to reduce other or lower in oxidation number.
The given reaction is :

act as an oxidizing agent.
The oxidation number of N in
is calculated as:
(+1)+(x)+3(-2) = 0
x = +5
And the oxidation number of N in
is calculated as:
(+1)+(x)+2(-2) = 0
x = +3
From the oxidation number method, we conclude that the oxidation number reduced this means
itself get reduced to
and it can act as an oxidizing agent.
act as a reducing agent.

The oxidation number of O in
is calculated as:
(+1)+(+5)+3(x) = 0
x = -2
The oxidation number of O in
is Zero (o).
Now, we conclude that the oxidation number increases this means
itself get oxidized to
and it can act as reducing agent.
We know that 1 mole of anything has a volume of 22.4 liters.
And 1 mole of N2 gas has a weight of 28 grams.
Comparing them , we get the answer as 5.31
Because it is a solid material, it is known as a dry lubricant. This is useful in applications where “wet” lubricants, such as oil, cannot be used<span>. </span>Graphite<span> is the only non-metal element that is a good conductor of electricity. Natural </span>graphite<span> is </span>used <span>mostly in what are called refractory applications.</span>