Electron Configuration

ground state

when all the electrons in an atom have the lowest possible energies

excited state

an electron in a temporarily higher energy level than in its ground state

what happens to an electron when it absorbs energy?

Jumps to excited state

what happens to an electron when it releases energy?

falls to ground state

electron configuration

the arrangement of electrons in the energy levels, sublevels and orbitals of atoms

Aufbau Principle

states that each electron occupies the lowest energy orbital available

Erwin Schroedinger

he gave rise to the Quantum Mechanical Model with his calculation of the probability of where an electron can be found around the atom

Pauli Exclusion Principle

maximum of two electrons may occupy an atomic orbital, but only if they have opposite spins

Hund's Rule

electrons occupy equal energy orbitals so as to maximize the number of unpaired electrons

electron cloud

a region around the nucleus of an atom where electrons are likely to be found (most probable location)

sublevels

regions within the energy levels; corresponds to the block grouping s,p,d,f on the Periodic Table

orbitals

regions within electron cloud where electrons orbit the nucleus; number of orbitals differs with sublevel type (s,p,d,f)

s orbitals

spherical orbitals; first to fill for any energy level; can only hold 2 electrons

p orbitals

3 mutually perpendicular dumbbell shaped orbitals; second to fill from 2nd energy level on up; can hold max of 6 electrons

d orbitals

5 orbitals of cloverleaf shape; third to fill for any energy level; beginning in the third shell, contains a total of 10 electrons; higher in energy than s and p orbitals in the same shell.

f orbitals

their shapes are even more complex than s, p, or d orbitals; can hold a total of 14 electrons in 7 sub-shells; in the fourth and fifth energy levels

energy levels

what do the coefficients stand for? (1s²)

sublevels (or orbitals)

what do the letter symbols stand for? (1s²)

The number of electrons in a sublevel

what to the superscripts stand for? (1s²)

quanta

Small specific amounts of energy; The amount of energy needed for an electron to jump from one energy level to the next

Nitrogen

name the element 1s²2s²2p³

Aluminum

name the element 1s²2s²2p⁶3s²3p¹

Titanium

name the element [Ar]4s²3d²

Tungsten

name the element [Xe]6s²4f¹⁴5d⁴

shorthand notation

uses noble gas configuration from the preceding full level (stable core), along with electrons on current level

valence electrons

an electron in the highest occupied energy level of an atom;available to be lost, gained, or shared in the formation of chemical compounds

photons

a quantum of light; a discrete bundle of electromagnetic energy that interacts with matter similarly to particles

Full Configuration for Mg

1s²2s²2p⁶3s²

Full Configuration for Rh

1s²2s²2p⁶3s²3p⁶4s²3d¹⁰4p⁶5s²4d⁷

# of orbitals in any s sublevel

1

# of orbitals in any p sublevel

3

# of orbitals in any d sublevel

5

# of orbitals in any f sublevel

7

How do you determine the # of Valence electrons?

by counting the # of s and p electrons since the most recent noble gas

Why do we fill the 4s orbital before the 3d orbital?

Because the 4s is lower in energy than the 3d, so it is filled first.

Electron Configuration for Si

1s²2s²2p⁶3s²3p²

Electron Configuration for Sr

1s²2s²2p⁶3s²3p⁶4s²3d¹⁰4p⁶5s²

Electron Configuration for Kr

1s²2s²2p⁶3s²3p⁶4s²3d¹⁰4p⁶

Electron Configuration for Ar

1s²2s²2p⁶3s²3p⁶