Question

How does an atom differ from a molecule? In what ways are they similar?

Answer 1

Explanation:

Difference between the two:

Atoms are defined as the smallest particle of a chemical element that exists. They are made up of protons, electrons and neutrons. Elements have similar kind of atoms present in them while compounds have different type of elements present in them.

Molecules are formed when two or more atoms of similar or different kinds bond together. For Example: $H_2O,N_2$ etc...

Similarity between the two:

A pure substance is defined as the substance which is formed by same or different type of atoms which are chemically combined in a fixed ratio by mass. Atoms and molecules are considered as pure substances.