Because it requires lots of electricity to turn it into an aqueous solution so that electrolysis can be performed on it.
Explanation:
Atomic number of carbon is 6. So, 4 valence electrons are present.
Therefore, it can form 4 covalent bonds with varying bond angles by sharing its valence electrons.
Catenation is also an important property of carbon. Catenation is bonding with atoms of same element. Carbon skeleton can be formed in any direction and can vary in length, branching, and ring structure.
Elements required for making most of the molecules in living organisms are:
C, H, N, O, P and S
Carbon easily form covalents with other 5 elements.
These properties make carbon most versatile building blocks of the molecules used by living organisms.
Ultraviolet light has higher frequency and higher radiant energy.
Look up a chart on electromagnetic radiation if you need further help.