What is the difference between an atom and an element?

An atom is the smallest part of an Element that can exist alone and retain the properties of that element. If you take, shall we say, 1.0 gram of a pure element, it will contain millions of atoms of that element.

Element is a basic substance like hydrogen, oxygen, gold, etc... Atom is the smallest amount of an element.

elements are made of atoms atoms are not made of elements refer to the periodic table

An atom is the smallest particle of matter that can exist in isolation. It is made of of electrons neutrons and protons and often will be neutrally charged. Matter can be decomposed by chemical or mechanical process to produce atoms. Breaking it apart into smaller pieces requires nuclear reactions and is not considered "chemistry". An element is that set of atoms which contain the same number of protons in their nucleus. (And when neutrally charged, the same number of electrons). All atoms of the element hydrogen contain 1 proton in their nuclei. All atoms of carbon contain 6. So an element is composed of a specific number of protons. An atom may contain between 1 and 118 protons in its nucleus. If you say atom, all I know is that it is small (there are about 3,000,000,000,000,000,000,000 atoms of hydrogen in 1 drop of water and ther are two elements in a drop of pure water, hydrogen and oxygen) An element is what we call a group of atoms of specific type. If each atom were a ceramic tile then (ignoring charge and isotopes) each element would be tlles of the same color, shape and size. And no two elements would have the same color and shape and size. You could build a building (a molecule) with one kind of tile or build it with many different types. But you could still see that the building was composed both of many atoms (tiles) and various elements (tiles of the same shape, color and size).

Atoms combine to form molecules; when all bound atoms are alike, they form elements.

An atom is the building block of everything in the universe. An element are large quantities of atoms put together that are all the same, ie, oxygen is made up of oxygen atoms.