Prove that a set with n elements has n(n ?1)(n ? 2)/6 subsets containing exactly three elements whenever n is an integer greater than or equal to 3.
Elements are abbreviated in scientific shorthand • Elements on the periodic table are abbreviated, • Some elements are abbreviated from their name • Sometimes the abbreviation is derived from Greek or Latin name ( for example, silver is Ag, which comes from the greek word for Argentum). • Some elements are named after scientists.(Es for Einsteinium, Lr for Lawrencium) • All elements consist of one capital letter or a capital letter and 1 or 2 lower case letters. Atom—smallest piece of matter that still has the properties of the element. • Atoms are comprised of subatomic particles— protons, neutrons and electrons *** Protons and neutrons are in the nucleus of an atom. *** Electrons on the other hand, occupy orbitals aka (also known as) electron clouds that s