Alpha (letter)

Common letters
Αα	Alpha	Νν	Nu
Ββ	Beta	Ξξ	Xi
Γγ	Gamma	Οο	Omicron
Δδ	Delta	Ππ	Pi
Εε	Epsilon	Ρρ	Rho
Ζζ	Zeta	Σσς	Sigma
Ηη	Eta	Ττ	Tau
Θθ	Theta	Υυ	Upsilon
Ιι	Iota	Φφ	Phi
Κκ	Kappa	Χχ	Chi
Λλ	Lambda	Ψψ	Psi
Μμ	Mu	Ωω	Omega
Uncommon letters
	Digamma		Qoppa
	San		Sampi
Other letters
	Stigma		Sho
	Heta
Greek alphabet

For other uses, see Alpha (disambiguation).

Alpha (uppercase/lowercase Α α), is the first letter of the Greek alphabet, used to stand for the "a" sound in Ancient and Modern Greek. In the system of Greek numerals, it has a value of 1. Letters that came from it are the Roman A and Cyrillic А.

Alpha is often used in physics and chemistry as a symbol or in the names of things, for example alpha particles (which are two protons and two neutrons bound together into a particle the same as a helium nucleus). The symbol is also used a lot in mathematics in algebra, for example naming angles.