Molecule
Aluminum is the element found in a compound called bauxite.
carbon monoxide
Diphosphonic Acid. I beleve.
sulphurdioxide
Radium is a chemical element; a compound has a minimum of two chemical elements.
An element and a compound can undergo a chemical reaction called a single replacement reaction. In this type of reaction, the element replaces one of the elements in the compound, forming a new compound and a different element as a product.
The elements a compound contains and the exact number of atoms of each element in one unit of that compound is referred to as the chemical formula of the compound.
That's because of the way "compound" is defined. If atoms of an element combine with other atoms of the SAME element, then it's not called a "compound".
It is simply called a molecule of an element. (ex: O2 is oxygen gas, H2 is hydrogen gas)
Steam is the vapour phase of the compound called water.
A binary compound of carbon with more electropositive element is called a Carbide
It is called a single displacement reaction.