Question

Which of the following are compounds?
(i) CO
(ii) Na
(iii) NO
(iv) Co
A I and ii
B ii and iii
C I and iii
D I and iv

Answer 1

Everything on this planet is a form of matter, which is defined as any material that occupies space and has mass. The matter is further subdivided into solid, liquid, and gaseous states. Aside from that, it's divided into pure substances and mixes.

Complete answer:
A chemical compound is a material made up of numerous similar molecules (or molecular entities) that are bound together by chemical bonds and contain atoms from many elements. As a result, a molecule made up of only one element's atoms is not a compound.
Depending on how the component atoms are kept together, there are four types of compounds:
Covalent bonding holds molecules together.
Ionic bonds hold ionic substances together.
Metallic bonds hold intermetallic compounds together.
Coordinate covalent bonds hold some complexes together.
A chemical compound is any material that has two or more different types of atoms (chemical elements) in a set stoichiometric proportion; the notion is most easily grasped when discussing pure chemical substances. Chemical compounds may be transformed into compounds or substances with fewer atoms via chemical reaction because they are made up of set proportions of two or more types of atoms. In the chemical formula, the ratio of each element in the compound is given as a ratio.
From the given options Na and Co are sodium and cobalt respectively.
A compound is a chemically bound group of two or more atoms of different elements that are electrically neutral. Because NO and CO are made up of atoms from two distinct elements, they are compounds.
The colourless gas nitric oxide has the formula NO. It is one of the most common nitrogen oxides. A free radical is nitric oxide.
Carbon monoxide is a gas that has a slightly lower density than air. One carbon atom and one oxygen atom make up carbon monoxide. It is the oxocarbon family's most basic chemical.

Hence option c is correct.

Note:
A chemical reaction can change the chemical makeup of a substance by interacting with another chemical component. In this process, links between atoms in both interacting molecules are broken, and subsequently bonds are rebuilt, resulting in new atom associations.