Bach, Johann Sebastian
Big Bang Theory
Khan, Hazrat Inayat
Khan, Pir Vilayat Inayat
Khan, Pir Zia
Pir o Murshid
The great variety of substances around us is made from different combinations of only a hundred or so atoms. The smallest part of a substance that still has all the properties of the whole is called a molecule. It is made of one or more atoms held together in one of two ways. Atoms in a molecule can share electrons, forming a covalent bond. Or, atoms may be attracted to each other by their opposite charges creating an ionic bond.
Molecules made of the same atoms can still have very different properties. For example a molecule of water is made of two atoms of hydrogen and one of oxygen (H20) while hydrogen peroxide is made of one atom of hydrogen and one of oxygen (OH-). Water is one of the best known solvents and hydrogen peroxide is an acid.
A molecule can be very simple, with only one or two constituent elements, or its complexity can be incredible, made of an uncountable number of atomic combinatinons held together with both covalent and ionic bonds. One molecule of water is is made of only three atoms, whereas a molecule of DNA contains many millions.