Chem - Electron subshells, orbitials, shells

order from largest to smallest

energy shell, subshell, orbitial, then electrons

list energy shells and amount of e in each

n=1 (2 max), n=2 (8 max), n=3 (18 max)

list the subshells

s, p, d, f

how many subshells can 3 shell hold

s, p, d

orbitals can hold up to

2 electrons in each max w opposite spins

how many orbitals are in each subshell?

s=1, p=3, d=5, f=7

how many e are in each subshell

s=2, p=6, d=10, f=14

how many orbitals can be in each subshell

s=1, p=3. d=5, f=7

what is an orbital

An orbital is a region of space where an electron is likely found

Shapes of orbitals

s=sphere, p=dumbbell

key rule of electron configration

$s fills before 3d

second ie definition

second ionisation energy is the energy required to remove one e from each ion in 1 mole of gaseous 1+ ions to form 1 mole of gaseous 2+ ions

requirements for ionisation

.- must be a gaseous atom
- always a positive energy change (endothermic) 

Exceptions to Know

Chronium is [Ar] 4s^1 3d^5

Copper is [Ar] 4s^1 3d^10

s-block in periodic table

Groups 1–2

p blocks

groups 3-0

d blocks

transition metals

Why does 4s fill before 3d

bc its a little less in energy

State the meaning of the term first ionisation energy.

Energy (needed) to remove one mole of electrons from one mole of atoms

Why is the 2nd or 3rd IE (4th etc) level alwayw greater than the last IE level?

Because after you remove an electron, the atom becomes more positive (stronger attraction between nucleus and remaining e) so the remaining e get clsoer to the nucleus and become harder to remove

Write an equation, including state symbols, to show the reaction that occurs when the second ionisation energy of magnesium is measured.

Mg+1 g —- Mg+2 + e-

Exceptions of IONisation trends

between group 2 to 3 - slight decrease. Electron is in the new p subshell has a weaker attraction to nucelus than the 2s and therefore easier to remove.

between group 5 and 6 (p drop)

occurs because the electron being removed from a Group 6 element is in a paired p-orbital, which is destabilized by electron-electron repulsion. This repulsion makes the paired electron slightly easier to remove compared to the unpaired electrons in G5

GENERAL TRENDS OF IE

Down group- IE decreases as the atomic radius increases so the outer e are further from nucleus, so there is a weaker attraction and its easier to remove.

Period- increases as there are more protons meaning more nuclear charge and electrons are in the same shell so there is a stronger attraction and more diff to remove. 

order of iE

1st ie level - removes one electron, then 2 etc , 3 - core e is removed

A sample of indium must be ionised before it can be analysed in a mass spectrometer. Q7(bi) State what is used to ionise a sample of indium in a mass spectrometer.

electron impact (USUALLY ALWAYS IS) electrospray is for big molecules like proteins etc 

) State why more than the minimum energy is not used to ionise the sample

to prevent further ionisation

Give two reasons why the sample must be ionised.

to be accelerated

So the ions can be detected at the detector

State and explain the difference, if any, between the chemical properties of the isotopes

There is none! Isotopes react the same

Suggest one reason why particles with the same mass and velocity can be deflected by different amounts in the same magnetic field.

Size of the charge

State and explain the general trend in first ionisation energies for the Period 3 elements aluminium to argon.

Increasing nuclear charge / increasing no of protons

There is a similar general trend in first ionisation energies for the Period 4 elements gallium to krypton. State how selenium deviates from this general trend and explain your answer.

lower - bc the paired p orbitals repel

If there is a sudden ie energy jump at level 3. that means what

that the first two levels were valence e and the removal is now core e

WHY must it be gaseous atoms to be ionised

this is so no other energy changes are involved. the energy involved is specifically to remove the electron

why must it always be endothermic for ionsation

so the enegry must be put in to pull e from nucleus

higher ie means

more diff to remove e

shielding

repulsion of the outer e by inner e to make them easier to remove. more shielding means a lower first ie

factors that affect IE

nuclear charge (more protons mean more + charge = more attraction= more diff to remove e)

distance from nucleus (attraction to nucleus drops as E gets further)

shielding This is because inner-shell electrons repel the outer electrons

first ie

energy required to remove one e from each ion in mole of gaseous ions to form 1 mole of gaseous 1+ ions

ie exceptions group 5 and 6

Thoccurs because the electron being removed from a Group 6 element is in a paired p-orbital, which is destabilized by electron-electron repulsion. This repulsion makes the paired electron slightly easier to remove compared to the unpaired electrons in a stable, half-filled p-orbital of a Group 5 element. 

group 2 and 3

ionisation drops due to the outer e being in a p orbital for the first time, so it is sightly shielded by complete s orbital reducing expected IE

do ie questions

because the electron being removed from a Group 3 element comes from a higher-energy, slightly further-out p-orbital, whereas Group 2 elements have their outer electron in a lower-energy s-orbital.