ABCDEFGHIJKLMNOPQRSTUVWXYZ

A

atomic mass unit
mass equivalency of 1 x 10-24gm
aufbau principle
atoms are "built up" through the progressive addition of electrons
average atomic mass
masses of all isotopes and their relative abundance (C = 12.01 a.m.u.)

B

C

D

d-orbital
four-leaf clover shaped orbitals - maximum of 10 electrons (dxy dxz dxz) and a donout shaped orbital along the xy plane

E

electron density
expression of probability when specifying the location of an electron in orbit

F

G

ground state
most stable electron configurations where electrons are in lowest possible energy state

H

heterogenous mixture
one where composition, color, properties will vary (e.g. sand)
homogenous mixture
one uniform throughout (e.g. air)

I

J

K

L

M

mixture
two or more substances - each with their own chemical identity

N

O

orbital
a specific distribution of electron density (quantum mechanical model)

P

p-orbital
dumbell shaped orbitals having two lobes- maximum of 6 electrons (px py pz)
pauli exclusion principle
an orbital can have a maximum of two electrons - with opposite spins
pure substance
properties and composition do not change from sample to sample

Q

R

S

s-orbital
spherical orbit with the lowest energy - maximum of 2 electrons

T

U

uncertainty principle
states the impossibility of knowing the exact location and momentum of an electron

V

W

X

Y

Z


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