Question

Which of the following cannot be broken down chemically?
(A) Anions
(B) Cations
(C) Element
(D) Isotope
(E) Atom

Answer 1

Only one kind of atom consists of an element. It cannot be broken down by physical or chemical means into a simpler type of matter, and it may exist as either atoms (e.g. argon) or molecules (e.g., nitrogen).

Complete Step-by-Step solution
Anions are ions which are negatively charged. They are formed when the electrons are obtained by non-metal. They gain one or more electrons and do not lose protons at all. They have, therefore, a net negative charge. Examples of anions are Calcium $\left(\mathrm{Ca}^{2+}\right)$ , Potassium $\left(\mathrm{K}^{+}\right)$ , hydrogen $\left(\mathrm{H}^{+}\right)$ . An anion can be broken down chemically.
Cations are ions which are positively charged. When a metal loses its electrons, they are formed. They lose an electron or more than one and do not lose any protons. They possess a net positive charge, therefore. Some examples of cations are calcium $\left(\mathrm{Ca}^{2+}\right),$ Potassium $\left(\mathrm{K}^{+}\right),$ hydrogen $\left(\mathrm{H}^{+}\right)$ . A cation can be broken down chemically.
A component is a species of atoms in the atomic nucleus with the same number of protons. A pure chemical substance composed of atoms in the atomic nucleus with the same number of protons. An element cannot be broken down chemically.
The variants of chemical elements that have the same number of protons and electrons, but a different number of neutrons, can be defined as isotopes. In other words, because of a difference in the total number of neutrons in their respective nuclei, isotopes are variants of elements that differ in their number of nucleons. Isotopes can be broken down chemically.
The building blocks of matter are atoms. These are the smallest and smallest individual particles that make up a substance. Atoms do not exist in the form of ions or molecules independently of their existence. The size of an isolated atom cannot be measured. Atoms can be broken down chemically.
Hence, the correct option is (C).

Note
The main reason is that elements are the simplest form of matter with distinctive and special characteristics. They are the most stable substance types and consist primarily of only one type of atom. Elements can thus not be broken down or separated into simpler substances by ordinary chemical or physical means.