Atomic Structure Flashcards
Ionisation Energies
What is the mass spectrum?
The mass spectrum is a set of an element indicating the mass and the abundance of each isotope present.
Define First Ionisation Energy
The energy required to remove the most loosely held electron from one gaseous atoms to produce one mole of gaseous ions each with a +1 charge.
What is an orbital?
A region of space within an atom that can hold up to two electrons with opposite spins, where there is a high probability of finding an electron.
Describe the subsells with number of electrons.
S - Orbital:2 electrons, sphere shaped
P- orbital - 6 electrons dumbbell shaped
D - orbital - 10 electrons
F orbital - 14 electrons
Describe the blocks of the Periodic Table.
s-Block - Group 1+2
p - Block - Group 3,4,5,6,7,8
d- block - Transition Metals
f - block - Inner transition metals
Describe how to fill atomic orbitals
Lowest energy orbitals gets filled first (Aufbau Principle)
Electrons occupy orbitals on their own and paus up when their are no more available(Hund’s Rule)
State the three factors affecting Ionisation Energy
- Nuclear Charge
- Shielding
- Distance from nucleus/subshell energy
Explain the trend in ionisation energy down a Group
- Shielding increases but is counter affected the number of protons increased down the group
- Distance from nucleus increases weakens the electrostatic force between the nucleus and outer electron
- Ionisation energy decreases
Explain the trend in ionisation energy across a period
- Nuclear Charge increases due to more protons
- Degree of shielding relatively the same
- Increase Nuclear Charge contacts the atomic radius decreasing the distance from the outer electron
- Ionisation energy decreases
Explain why there is a decrease in 1st I.E Be and B
- Be 2s subshell
- B 2p subshell
2p subshell higher energy therefore lower I.E
Explain why there is a decrease in 1st Ionisation Energy in Phosphorus and Sulphur
- Phosphorous 3p3
- Sulphur 3p4
- Added electron repulsion in sulphur p orbital causing lower ionisation energy
Explain the trend in Successive Ionisation Energies in Na between the 1st and 2nd
- Big increase in ionisation energy
- Shielding decreases due to electron being removed from outer electron
- Electrons are closer causing a greater nuclear charge and therefore ionisation energy
Explain the trend in Successive Ionisation Energies in Na between the 3rd and the 11th
- Ionisation Energies steadily increases as the the cations increase their positive charge
- same shielding
- radius decreases due to greater lower elctron to proton ratio
Define ‘Relative Atomic Mass’
The average mass of an atom of an element relative to a 1/12 of the mass of carbon-12 atom.
Define ‘Relative Isotopic Mass’
The average mass of an atom of an isotope relative to the 1/12 of the mass carbon-12 atom.
