S1.3 (Electron Configuration)

Question 1

Emission Spectra

Answer 1

Range of frequencies or wavelengths of electromagnetic radiation emitted during an electron transition from a higher energy to a lower energy level shown by lines converging at higher energy

Question 2

Electron Transition

Answer 2

Movement of an electron between energy levels in an atom

Question 3

electromagnetic Spectrum

Answer 3

Radiowaves<Microwaves<Infra red<Visible Light<UV<X Ray< Gama Ray

Question 4

highest energy & frequency wave

Answer 4

UV

Question 5

continuous spectrum

Answer 5

all the freuencies across a range of electromagnetic radiation (rainbow)

Question 6

Emission line Spectra (How it works)

Answer 6

• energy is applied to a sample of vaporized hydrogen
• only shows specific wavelengths: colored lines on black sheet of paper
  *

Question 7

Why electrons prodcue colored lines

Answer 7

1. electron absorbs energy
2. n=2 -> n=3
3. electron is excited & unstable
4. electron releases energy
5. n=3 -> n=2
6. emitted energy is shown as wave
7. line is observed

Question 8

What is special about the lines on an emission spectra sheet

Answer 8

they converge at high frequencies

Question 9

Hydrogen Emission Spectrum

Answer 9

The emission line spectrum of hydrogen (proves that electrons stay at specific energy levels)

Question 10

Hydrogen Emission Spectrum

UV

Answer 10

higher -> n=1

Question 11

Hydrogen Emission Spectrum

Visible Light

Answer 11

higher -> n=2

Question 11

Hydrogen Emission Spectrum

IR

Answer 11

higher -> n=3

Question 12

meaning of n=∞

Answer 12

point where the electron has left the atom thus having an infinite amount of energy

Question 13

Heisenbergs uncertainty principle

Answer 13

it is impossible to know the postion and momentum of an electron at once

Question 14

principle quantum numbers

Answer 14

shows main energy levels of an electron (n)

Question 15

Orbital

Answer 15

A region of space with the highest possibility of finding an electron

Question 16

How many electrons can each/any orbital hold

Answer 16

2

Question 17

S orbital

Answer 17

• spehrical
• lowest in energy
• size increases as shell number increases

Question 18

Total number of orbitals in each energy level

Answer 18

• n=1; 1
• n=2; 4
• n=3; 9
• n=4; 16

Question 19

P Orbital

Answer 19

• dumbell shaped
• has 3 degenerate orbitals (Py, Px, Pz)
• total of 6 e-

Question 20

D Orbital

Answer 20

• double dumbel shaped
• 5 orbitals
• can hold a total of 10 e-

Question 21

F orbital

Answer 21

• 7 orbitals
• total of 14 e-

Question 22

Total number of electrons in each energy level

Answer 22

• n=1; 2
• n=2; 8
• n=3; 18
• n=4; 32

Question 23

Sublevels in each energy level

Answer 23

• n=1; 1s
• n=2; 2s,2p
• n=3; 3s,3p,3d
• n=4; 4s,4p,4d,4f

Question 24

Aufbau Principle

Answer 24

Electrons fill the lowest energy levels first and fill orbitals in order of increasing energy

Question 25

Hunds Rule

Answer 25

When degenerate orbitals are available, electrons will fill those orbitals singly and with parallel spins before pairing up

Question 25

Pauli Exclusion Principle

Answer 25

Two electrons in the same orbitals must have opposite spins

Question 25

Aufpau Principles filling order

Answer 25

1s>2s>2p>3s>3p>**4s>3d**>4p>5s>4d>5p>6s

Question 26

# Noble Gas Notation example Calcium (20 e-)

Answer 26

(Ar)4s2

Question 26

Shortened Spectroscopic Notation/ Noble Gas notation

Answer 26

factors out the part of the notation which overlaps with one of the noble gases

Question 26

# Spectroscopic Notation Exceptions

Answer 26

* copper * chromium they first fill the d orbitals singly rather having them half full

Question 27

Orbital box Notation

Answer 27

shows electrons and their pairing + spins

Question 28

Eelectron configurations of ions

Answer 28

* filling= lowest first * removing= highest first * except: 4s first in & first out

Question 29

Ionisation Energy

Answer 29

The amount of energy required to remove one mole of electrons from one mole of gaseous atoms

Question 30

Why ionisation energy increases across a period

Answer 30

* nuclear charge increases as protons increase * this means stronger attraction between nucleus and electrons * energy required to remove the outer electrons increases

Question 30

Trend in ionisation energies

Answer 30

* ionistaion energy increases across a periods * ionisation energy decreases going down a group

Question 31

Why ionisation energy decreases down a group

Answer 31

* number of shells increase, increasing the distance from nucleus and electrons * attraction between electrons and nucleus decreases => easier to remove electrons * &shielding from electrons in shells decreases attraction => energy required to remove an electron decreases

Question 32

Convergence limit

Answer 32

en electron is removed from the attraction of the nucleus (ionised)

Question 33

# While knwoing the frequency ionisation Energy calculations (kJ/mol)

Answer 33

1. use E=hf to calculate energy in Joules 2. then divide by 1000 for kJ 3. then times by avogadros constant (L) for K+kJ per mole

Question 34

# Without knowing the frequency Ionisation energy calculations (kJ/mol)

Answer 34

1. f=c/λ and E=Lhf (per mole) so subtitude f into E=Lhf 2. E=Lhc/λ 3. to get in in kJ = E= LHC/1000λ

Question 34

Succesive Ionisation Energies

Answer 34

process of removing successive electrons from an atom or positive ion

Question 34

Important about the second ionisation energy

Answer 34

It is always significantly larger than the first as you're trying to remove an electron from a positive ion meaning the attraction to the nucleus is greater ## Footnote (the more you need to remove the larger the ionisation energy)

Question 35

Deducing valence electrons based on ionisation energy

Answer 35

the ionisation energy difference which is the largest means that was the last electron in the shell that was being removed

Question 36

why is there a general increasing value for ionization energy across a period

Answer 36

electrons are being added to the same energy level, but the amount of protons increases => this means the attraction between them gets stronger

Question 37

Things to look out for when comparing ionization energies (especially graph)

Answer 37

* trends across period (ionization increases) * trend across groups (ionization increases down) * DRAW ELECTRON CONFIGUARTION and speak about energy levels

Question 38

What happens to ionisation energy when electrons are paired vs unpaired

Answer 38

* if all are unapired = harder to remove 0 ionisation energy increases * if some are paired & unpaired= paired ones are easier to remove due to repulsion = decreases ionisation energy

Question 39

Evidence that electrons exist in fixed energy levels

Answer 39

* emission spectra is discrete lines (if continuous: electrons would be anywherre) * the lines converge showing different energy levels as the lines are succesively converging * the differneces in ionization energies shows that different energies are needed to remove from different levels

Question 40

limitations of hydrogen emission spectra

Answer 40

* does not represent sub levels/orbitals * only applies to hydrogen atom/atom of one electron * does not explain why only certain energy levels allowed * the atom is considered to ber isolated * does not consider the number of electrons thta can fit into a energy level * does not consider the probability of finding an electron (orbitals)

Question 41

emission spectrum described

Answer 41

* series of lines * only at specific wavelengths * converge at high frequences

Question 42

relationship of emission spectrum tp hydrogen atom (outlined)

Answer 42

* electron transition between high energy level to lower energy level * DRAW DIAGRAM

Question 43

converting nm to m

Answer 43

multiply by 10xe9

Question 44

things to consider when speaking about ionisation enrgy trends

Answer 44

* shielding => more shielding = less attaraction * which orbital/subshell or main energy level it is taking e- out of * attraction to nucleus (is it already psotive or negatively charged?)