1.1 Atomic Structure Part 2 Flashcards
What does each sub-shell consist of?
Orbitals
What is an orbital?
A region which can hold a maximum of two electrons with opposite spins
What is the complete electronic configuration of oxygen?
1S2, 2S2, 2P4
What is the complete electronic configuration of silicon?
1S2, 2S2, 2P6, 3S2, 3P2
Give the complete electronic configuration of potassium
1S2, 2S2, 2P6, 3S2, 3P6, 4S1
What is the complete electronic structure of titanium?
1S2, 2S2, 2P6, 3S2, 3P6, 3d2, 4s2
What is the electronic configuration of chromium?
1s2, 2s2, 2p6, 3s2, 3p6, 3d5, 4s1
What is the complete electron configuration of copper?
1s2, 2s2, 2p6, 3s2, 3p6, 3d10, 4s1
What are the two elements that don’t follow the complete electronic structure pattern?
Copper and chromium (Cu and Cr)
What is the complete electronic configuration of an Na+ ion?
1s2, 2s2, 2p6
What is the complete electronic configuration of an Mg 2+ ion?
1s2, 2s2, 2p6,
What is the complete electronic configuration of a Cl- ion?
1s2, 2s2, 2p6, 3s2, 3p6
What is the complete electronic configuration for a S 2- ion?
1s2, 2s2, 2p6, 3s2, 3p6
What is first ionisation energy?
The energy needed to remove one mole of electrons from one mole of atoms in the gaseous state
The first ionisation energy of sodium is the energy required for the following process:
Na(g) -> Na+(g) + e-
What are the units for ionisation energy?
kJmol-1
What are the factors, in order, that influence first ionisation energies?
- shielding
- distance
- nuclear charge
Why does shielding influence first ionisation energies?
Increased shielding lowers the attraction of the outer electron ( more inner e- the lower the ionisation energy)
Why does distance influence first ionisation energies?
The further away from the nucleus the e- is, the lower the attraction (1st ionisation energy decreases with increased distance)
Why does nuclear charge influence the 1st ionisation energies?
The higher the nuclear charge the more attraction to the e- ions (more protons, higher 1st ionisation energy)
What happens to the 1st ionisation energy as you go down a group?
It decreases
Why does 1st ionisation energy decrease as you go down a group?
Shielding: increases, lower attraction
Distance: increases, lower attraction
Nuclear Charge: increases
Summary: 1st ionisation energy decreases as shielding and distance outweigh nuclear charge
What happens to the 1st ionisation energy as you go across a period?
Increases
Why does 1st ionisation energy increase across a period?
Shielding: Similar
Distance: DECREASES, attraction increases
Nuclear charge: Increases, attraction increases
Summary: attraction increases so 1st ionisation energy increases
What is the clue to use the A-level structure stuff when answering questions on the trends in first ionisation energies?
It says there is a SMALL dip or increase
What happens to the first ionisation energy between group 2 and 3 elements?
There is a small dip
Why is there a small dip in first ionisation energies between group 2 and 3 elements? E.g Be -> B
The outer electron in boron is the first in the 2p subshell. So it is slightly further from the nucleus, so attraction decreases slightly
Why is there a small dip in 1st ionisation energy between nitrogen and oxygen and again at phosphorous and sulfur?
Oxygen is the first element to have a pair of electrons in the 2p subshell. This creates some repulsion so the 1st ionisation energy decreases slightly
Why is there a big drop in ionisation energy between the end of one period and the start of the next?
Shielding: Increases, lower attraction
Distance: Increases, lower attraction
Nuclear charge: small increase
Summary: The large increases in shielding and distance outweigh the small increase in nuclear charge. Lower attraction, lower 1st ionisation energy
What is the first ionisation energy of mg?
Mg(g) -> Mg+(g) + e-
STATE SYMBOLS ARE IMPORTANT
What is the second ionisation of Mg?
Mg+(g) -> Mg2+(g) + e-
Write an equation for the second ionisation energy of neon and explain whether this value will be higher or lower than the first ionisation energy of neon
Ne+(g) -> Ne2+(g) + e-
The distance is slightly smaller so it is harder to remove the electron
