Flashcards in L5 & 6: The Electronic Configuration of the Atom Deck (50):

1

## What is 'Heisenberg's uncertainty principle'?

### You can never know both the position and the momentum of an electron at the same time

2

## What is 'the Aufbau principle'?

### Electrons enter the lowest available energy level first

3

## What is 'Hund's rule of maximum multiplicity'?

###
When in orbitals of equal energy, electrons will try to remain unpaired.

Bus rule: When you get on a bus, you go for the vacant row before sitting next to another person

4

## What is the 'Pauli exclusion principle'?

### No two electrons can have the same four quantum numbers. Only 2 electrons can go in each orbital, providing they are of opposite spin.

5

## How can an electron jump up to a higher energy level?

### Absorbing a photon of light

6

## How can an electron descend an energy level?

### Emitting a photon of light

7

## How can you determine the amount of energy between energy levels?

### Measure the energy of the photon emitted by a descending electron

8

## What is 'a measure of the amount of energy needed to remove electrons from atoms or ions'?

### Ionisation energy

9

## Define 'first ionisation energy'

### The energy required to remove one mole of electrons from one mole of gaseous atoms to form one mole of gaseous positive ions

10

## Are ionisation energies positive or negative? Why?

### Positive - to overcome the attraction between an electron and the protons in the nucleus, energy must be added to the system.

11

## True or false: lower nuclear charges result in higher ionisation energies

###
False. Higher nuclear charges result in higher ionisation energies.

The greater the pull of the nucleus, the harder it is to pull an electron away. Therefore, more energy is required.

12

## Define 'electron affinity'

### The amount of energy needed to add electrons to atoms or ions

13

## What is 'the energy needed to add one mole of electrons to one mole of gaseous atoms to form one mole of gaseous negative ions'?

### First electron affinity

14

## Are electron affinities positive or negative?

### Negative. Energy is released when electrons are added to an atom

15

## True or false: The more negative the electron affinity, the more stable the negative ion that is formed

### True

16

## True or false: Atomic size increases along a period and down a group

### False. Atomic size decreases along a period; increases down a group

17

## True or false: First ionisation energy increases across a period

### True

18

## True or false: First ionisation energy increases down a group

### False. First ionisation energy decreases down a group

19

## True or false: Patterns of first ionisation energy are opposite to the patterns of atomic size (i.e. as atomic size increases, 1st I.E. decreases, and vice versa)

### True

20

##
Fill in the gaps:

First electron affinity becomes _____(1)______ negative across a period, and _____(2)_____ negative down a group.

###
(1) more

(2) less

21

## What are the three most important factors to take into account when explaining trends in the periodic table?

###
1) Charge

2) Shielding

3) Atomic size

22

## What are the four quantum numbers required to specify the character of an electron?

###
1) Principal (n)

2) Azimuthal or subsidiary (l)

3) Magnetic (m)

4) Spin (s)

23

## What three things can be determined by the principal quantum number (n)?

###
1) Distance of electron from the nucleus - higher n = further from nucleus

2) Energy of electron - higher n = higher energy e-

3) Number of electrons a shell can hold - 2n^2

24

## How many electrons can L-shell hold?

###
8

L-shell n = 2

2n^2 = 2 x (2^2) = 2 x 4 = 8

25

## How many electrons can N-shell hold?

###
32

N-shell n = 4

2n^2 = 2 x (4^2) = 2 x 16 = 32

26

## What is the rule for allowed values of n?

### n = value greater than 0

27

## What do the azimuthal or subsidiary values correlate with?

###
The subshells.

l = 0 = s-subshell

l = 1 = p-subshell

l = 2 = d-subshell

l = 3 = f-subshell

28

## What is the rule for allowed values of l?

### l = 0 to (n-1)

29

## If n = 3, what are the allowed values of l?

### l = 0, 1, 2

30

## If n = 1, what are the allowed values of l?

### l = 0

31

## How many electrons can a given subshell hold?

### Calculate using formula 2(2l+1)

32

## What is the maximum number of electrons that can be held in the d subshell?

###
10

d-subshell l=2

2(2x2+1) = 4+1 = 5

5 x 2 = 10

33

## Which subshell is spherical?

### S-subshell (l=0)

34

##
What shape is the orbital represented by l=2?

A) Spherical

B) Dumbbell

C) Complex

D) Most complex

###
C) Complex

l=2 is the d-subshell, which is a complex shape.

35

## True or false: Putting the n value and the l value together (nl) gives you the specific subshell number

###
True.

E.g. Shell M, n=3, l=0 is the 3s subshell; l=1 is the 3p subshell....etc

36

## What is the rule for allowed values of m?

### m = value ranging from -l to +l, including 0

37

## If l=0, what are the allowed values of m?

### m = 0

38

## If l=2, what are the allowed values of m?

### m = -2, -1, 0, +1, +2

39

## If n = 3, what is the maximum allowed value of m?

###
+2

Max value of l=2, therefore the max value of m = +2

40

## What does the spin quantum number show?

### Whether the electron is spinning clockwise (+1/2) or anticlockwise (-1/2)

41

## If there are two electrons in the same orbital, what will their s values be?

### One will be +1/2 and the other will be -1/2

42

## What is the rule for allowed values of s?

### s = -1/2 or +1/2

43

## Which principle states 'you cannot determine the position and momentum of an electron at the same time'?

### Heisenberg's Uncertainty Principle

44

## Which principle states 'electrons enter the lowest available energy level first'?

### The Aufbau Principle

45

## Which principle states 'when in orbitals of equal energy, electrons will try to remain unpaired'?

### Hund's Rule of Maximum Multiplicity

46

## Which principle states 'No two electrons can have the same four quantum numbers'?

### Pauli Exclusion Principle

47

## True or false: In transition metals, electrons in the 4s orbital are removed before any electrons in the 3d orbitals

### True

48

## While analysing an element's successive ionisation energies you notice that there are some large jumps that are significantly larger the others. What does this tell you?

### A large jump in ionisation energy indicates a change in energy level

49

## What is different about the orbital filling of chromium and copper?

### When the d-orbital is almost full, or almost half full, it can steal an electron from the preceding s-orbital

50