unit 3/Ch. 5 - Structure and Periodic Properties

Order of Orbital filling

Valence electrons:

• Electrons in valence shell & unfilled d or f orbital

Screening

Pauli exclusion principle

• No two electrons can have the same set of values for quantum number in an atom (n, l, ml, ms)

Aufbau principle

• 1s 2s 2p 3s 3p 4s 3d 4p 5s 4d 5p 6s 4f 5d 6p 7s 6d 7p

• Adding electrons to lowest energy level first

Unpaired e-

• Can exhibit magnetic behaviour

Paramagnetic (attracted)

• unpaired e- in more than 1 orbital, strongly attracted to magnetic fields

Diamagnetic (not attracted)

• materials have no unpaired electrons, weakly repelled by magnetic fields

Atomic radius

• beeg vs small orbitals (due to atomic number)

Ionization energy (IE)

• energy required to remove an e-

Electron Affinity (EA)

• how much an atom accepts e-

Ionic radius

• - ions are bigger

• + ions are smaller

lattice energy

the energy required to convert one mole of an ionic solid into gaseous iconic constituents?

high LE:

• small radii & large charge

Atomic number

Z