Lecture 5/6-The Electronic Configuration Of The Atom

Question 1

Where are e- in an atom?

Answer 1

In stable energy levels

Question 2

What does the absorbtion of a photon of light do?

Answer 2

Allow the e- to jump to a higher level

Question 3

What does the jumping down of an e- to a lower level do?

Answer 3

Emits a photon of light

Question 4

If you measure the energy of the photon that has jumped up + down, what will you find?

Answer 4

The energy difference between levels (they are not evenly spaced)

Question 5

What is 1st ionisation energies?

Answer 5

The energy required to remove 1 mole of e- from 1 mole of gaseous atoms to form one mole of positive ions

Question 6

Why are ionization energies positive?

Answer 6

Energy must be put into the system to pull the negative e- away from the positive protons

Question 7

Why does higher nuclear charge have a higher ionization energy?

Answer 7

Because there is a greater pull of the nucleus on the e-

Question 8

What is e- affinity?

Answer 8

The energy required to add 1 mole of e- to 1 mole of gaseous atoms to form 1 mole of gaseous negative ions

Question 9

Cl-(g) + e- —> Cl-(g)

Answer 9

E- affintiy

Question 10

The more negative the e- affinity the ……

Answer 10

more STABLE the negative ion

Question 11

Why is the 2nd e- affinity positive?

Answer 11

Because energy needs to be put in to add e- to a negative ion

Question 12

Atomic size trends

Answer 12

Increases down a group

Decreases across a period

Question 13

1st Ionization energy trends

Answer 13

Decrease down the group

Increase across a period

Question 14

1st E- affinity trends

Answer 14

Less negative down a group

More negative across a period

Question 15

What are orbitals?

Answer 15

Regions in space where there’s a 95% probability finding a particular e-

Question 16

What does the quantum number n indicate

Answer 16

• The distance of an e- from the nucleus
• The energy of an e-
• Number of e- a shell can hold

Question 17

The higher the quantum number n the?

Answer 17

The further away from the nucleus the e- is

Question 18

Higher energy e- are less tightly held and so….

Answer 18

more easily removed (higher n)

Question 19

n can have how many electrons?

Answer 19

2n^2

Question 20

How many e- can:
K shell
L shell
M shell
N shell
have?

Answer 20

K shell n=1 ,so e- = 2
L shell n=2 ,so e-=8
M shell n=3 ,so e-=18
N sheel n=4 ,so e-=32

Question 21

What is a subshell?

Answer 21

A group of orbitals with the same energy

Question 22

The value of l depends on what quantum number?

Answer 22

n

Question 23

What values can l have?

Answer 23

From 0 to n-1

Question 24

What are spin quantum numbers?

Answer 24

The clock-wise + anticlockwise spinning of e- produces opposite magnetic fields

Question 25

Why is Gd3+ used for medical imaging?

Answer 25

The 7 unpaired electrons have the same spin (½) but a much smaller size than protons so it can be magnetized @RT

Question 26

What other ions/elements can be used for medical imaging?

Answer 26

Iron , nickel , cobalt

Question 27

What does the Azimuthal quantum number indicate?

Answer 27

The subshell an e- is in

Question 28

``` If the value of l is: -0 -1 -2 -3 what subshell is it in? ```

Answer 28

0=s 1=p 2=d 3=f

Question 29

Does the energy of the subshell increase with increasing of l?

Answer 29

YES

Question 30

What is the maximum number of e- a given subshell can hold?

Answer 30

2(2l+1)

Question 31

``` If l is 0=s 1=p 2=d 3 =f then how many e- can it hold ```

Answer 31

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

Question 32

``` What is the shape of the: s orbital p orbital d orbital f orbital ```

Answer 32

``` s = spherical p = dumbbell d = more complex f = still more complex ```

Question 33

What do magnetic quantum numbers represent ? (m/m1)

Answer 33

The orbitals in a given subshell

Question 34

What do magnetic quantum numbers indicate?

Answer 34

The direction of a particular orbital relative to the magnetic field/axes

Question 35

Does magnetic quantum numbers indicate energy?

Answer 35

NO

Question 36

m can have an integral value of what?

Answer 36

-1 through 0 to +1

Question 37

For a given value of l, total number of m value is what?

Answer 37

(2l+1)

Question 38

Heisenberg's uncertainty principle

Answer 38

You cannot determine the position + momentum of an e- at the same time

Question 39

Aufbau principle

Answer 39

E- enter the lowest available energy level 1st

Question 40

Hund's rule of max multiplicity

Answer 40

When in orbitals of equal energy , e- will try to remain unpaired (minimises repulsion between like charges , so the system is more stable)

Question 41

Pauli exclusion principle

Answer 41

No 2 e- can have the same 4 quantum numbers | -Only 2 e- can go in each orbital , if they're of opposite spin

Question 42

What are the special cases / exceptions?

Answer 42

``` Chromium = 4s1 3d5 Copper = 4s1 3d10 ```

Question 43

A large jump between successive ionisation energy indicates what?

Answer 43

A change in energy level from which the e- has been removed