What is amphoteric ??? give examples​

An amphoteric substance is one that can act as either an acid or a base, depending on the medium. The word comes from the Greek amphoteros or amphoteroi, meaning "each or both of two" and, essentially, "either acid or alkaline."

Amphiprotic molecules are a type of amphoteric species that either donates or accepts a proton (H+), depending on the conditions. Not all amphoteric molecules are amphiprotic. For example, ZnO acts as a Lewis acid, which can accept an electron pair from OH but cannot donate a proton.

Ampholytes are amphoteric molecules that exist primarily as zwitterions over a given pH range and have both acidic groups and basic groups.

Here are some examples of amphoterism:

Explanation:

Hope this helps! :P

hydrocarbons are organic compounds that contain only hydrogens and carbons. they can be saturated (those which contain only carbon-carbon single bonds) or unsaturated (those which contain carbon-carbon double or triple bonds) in nature. hydrocarbons can undergo several reactions like substitution, elimination etc.  

on substituting one or more hydrogen atoms in hydrocarbon it results in the formation of haloalkane. as the halogen atoms are large compared to the carbon and hydrogen atoms, due to which the molecular weight increases and the bond become polar because of presence electronegative halogen atom and results in the increase in boiling point of the haloalkane.

thus, the correct option is (b) that is the boiling point of the new compound increases on substituting a hydrogen atom with a halogen in a hydrocarbon.