Answer:
Elements and compounds cannot be broken down into simpler substances by an ordinary process because of the following reasons.
1) Elements cannot be broken down by chemical or physical methods because elements is composed of atoms which are indivisible.
2) Compound cannot be broken down into simpler substances by ordinary process because elements present in the compound are combined with each other chemically.
The correct answer is option B, that is, functional group.
A functional group refers to a part of a molecule, which is a classified/recognizable group of bound atoms. The functional group provides the molecule with its characteristics, in spite of what molecule comprises it, they are the centers of chemical reactivity. The functional groups in a molecule require to be determined when naming.
Scientific names follow a specific set of rules. Scientists use a two-name system called a Binomial Naming System. Scientists name animals and plants using the system that describes the genus and species of the organism. The first word is the genus and the second is the species.