Answer:
The anwser you are looking for is 4
Explanation:
Reason1: electrons on farther layers become free easyer
2nd reason: volume of atoms grows (from Helium to Xeon) so instead of boyle-mariot law equation (PV=vRT) is more accurate to use van der walls equations that adds to the boyle-mariot equation the volume occupied by the atoms of the gas to the volume of the space between the atoms P(Vm-b)=vRT
Your answer is C hope that helped
Explanation:
Nitrous acid is prepared in situ from hydrochloric acid and sodium nitrate because it is a weak acid and unstable. It only exists in an aqueous solution.
![H^++NO_{2}^{-}\rightarrow HONO](https://tex.z-dn.net/?f=H%5E%2B%2BNO_%7B2%7D%5E%7B-%7D%5Crightarrow%20HONO)
Nitrous acid is an unstable acid which gets decompose into the water , nitrogen dioxide and nitrogen monoxide gas.
![2 HNO_2 \rightarrow NO_2 + NO + H_2O](https://tex.z-dn.net/?f=2%20HNO_2%20%5Crightarrow%20NO_2%20%2B%20NO%20%2B%20H_2O)
Whereas nitric acid is highly stable acid which can be easily prepared from its reagent and it can easily be stored for future use.
It is option A- unburnt carbon