There are TWO atoms in one molecule of hydrogen.
Answer:
Only
gives spontaneous reaction.
Explanation:
A redox reaction will be spontaneous if standard reduction potential (
) of the reaction is positive. Because it leads to negative standard gibbs free energy change (
), which is a thermodynamic condition for spontaneity of a reaction.

Where
and
represents standard reduction potential of reduction half cell and standard reduction potential of oxidation half cell.
(1) Oxidation:
; 
Reduction:
; 
So, 
Hence this pair will give spontaneous reaction.
(2) Similarly as above, 
Hence this pair will give non-spontaneous reaction.
(3) Similarly as above, 
Hence this pair will give non-spontaneous reaction.
(4) Similarly as above, 
Hence this pair will give non-spontaneous reaction.
P waves are faster S wave are slower P waves can pass through both solids and liquids S waves bounce of solids
"Endothermic" is the way among the following choices given that you would <span>classify the following chemical reaction, in terms of energy. The correct option among all the options that are given in the question is the second option or option "B". I hope that the answer has come to your help.</span>
Shale actually forms in the part of the rock cycle called compaction.