12. Atomic Structure (HL)

Energy required to remove one electron from each atom in one mole of gaseous atoms under standard conditions

kJ/mol

6.63 x 10^-34 Js

Energy = hv (Planck’s constant x frequency of light)

c= v x lambda (frequency x wavelength)

E= hc/lambda a.k.a the energy of photons

Energy required to remove one mole of electrons from one mole of gaseous atoms to produce one mole of gaseous 1+ ions

Mg+ –> Mg2+ + e-

They have to be added to overcome electrostatic attraction between nucleus and valence electrons hence it is endothermic

As first electron is removed, effective nuclear charge increases and charge becomes positive. Increase in attraction means more energy is required to overcome

You have to multiply e=hv into 6.02*10^23 as you are calculating for 1 mole (Unit becomes kJ/mol)

It is the energy absorbed from n=1 to n=infinity

Consecutive energies required when removing electrons until only nucleus remains

• Proton number • Shielding effect • No. of energy levels • Atomic radius • Effective nuclear charge

It decreases as: • proton number increases but • energy levels increase • shielding effect increase so effective nuclear charge decreases

It generally increases as: • proton number increases • shielding effect remains the same so effective nuclear charge increases and is hence stronger requiring more energy

Magnesium has a higher first ionization energy because it has a complete s subshell while Aluminum has one valence electron in a p subshell making it easier to remove than Magnesium

Phosphorus has higher first ionization energy than sulfur because it has 3 half paired orbitals while sulfur has 1 paired orbital. It’s easier to remove a paired electron because of repulsion and so sulfur has a lower first ionization energy

It is in Group 2 because biggest jump is between 2nd and 3rd ionization energy so it likely has 2 valence electrons as it is harder to remove an electron from a stable configuration and one that’s closer to the nucleus