Every material is always made up of one or two elements of the periodic table.  An element is a type of substance that cant be broken down. 
There are exactly 92 elements. Every element is listed in the periodic table. Every single element has its own symbol to represent the element.
The smallest part of an element is an atom. All elements are one type of atom. All the atoms in an element are the same. 
A property of a substance is equivalent to a property of many atoms. It isn't just one single atom. An atom in one element will be different from an atom in another element. 
A compound is a type of substance made up of atoms for one or two elements which are joined together. Like atoms, the properties of a compound is different to the properties of an element that its made from. 
A molecule is a group of two or more atoms that are joined together. A formula shows the number of atoms in each element from a compound.