The smallestparticle of a chemical element that can exist
Sub-Atomic Particles
Protons
Neutrons
Electrons
Nucleus
The centralregion of the atoms
Element
A substance that cannot be broken down into two or more substance by chemical means
Examples of elements
Hydrogen [H]
Oxygen [O]
Compound
A material that consists of atoms of two or more different elements chemically bonded together
Compound
A material that consists of atoms of two or more different elements chemically bonded together. The elements in a compound are present in fixed proportions by mass. The properties of a compound are different from those of its constituent elements. For example, water (H2O) is a compound made up of hydrogen and oxygen atoms.
Element
A pure substance that cannot be broken down into simpler substances by chemical reactions. Each element is characterized by the number of protons in its atoms, known as its atomic number. There are 118 known elements, including hydrogen, oxygen, and iron.
