Greek Alphabet

Letter Name	Capital	Lowercase	Notes on common usage
alpha	Α	α	α = alpha particle/radiation (24α) or a type of protein structure (α helix)
beta	Β	β	β = beta particle/radiation (–10β) or positron (+10β), a type of protein structure (β sheet), or a type of oxidation (β-oxidation).
gamma	Γ	γ	γ = gamma radiation (00γ)
delta	Δ	δ	Δ = a change;  δ+ or  δ– = a partial charge
epsilon	Ε	ε	ε = molar absorptivity
zeta	Ζ	ζ
eta	Η	η
theta	Θ	θ	θ = an angle
iota	Ι	ι
kappa	Κ	κ
lambda	Λ	λ	λ = wavelength of light
mu	Μ	μ	μ = micro (unit prefix), dipole moment, or population mean
nu	Ν	ν	ν = frequency of light
xi	Ξ	ξ
omicron	Ο	ο
pi	Π	π	Π = osmotic pressure;  π = a type of bond or orbital
rho	Ρ	ρ	ρ = density
sigma	Σ	σ	Σ = summation;  σ = a type of bond/orbital or standard deviation
tau	Τ	τ
upsilon	Υ	υ
phi	Φ	φ	Φ = work function
chi	Χ	χ	Χ or χ = mole fraction or electronegativity
psi	Ψ	ψ	ψ = wave function
omega	Ω	ω	Ω = ohm (unit of resistance); ω = double bond position in a fatty acid (ω-6 fatty acid)