electronic configuration

Question 1

what are electrons shells labelled with

Answer 1

a principle quantum number (n)

Question 2

the higher the value of n….

Answer 2

… further away it is from the nucleus

Question 3

the further the shell is from the nucleus…

Answer 3

….the higher the energy associated with the shell

Question 4

what does each shell have a limit for

Answer 4

the number of electrons it can hold

Question 5

how many electrons can the n=1 shell hold

Answer 5

2

Question 6

how many electrons can the n=2 shell hold

Answer 6

8

Question 7

how many electrons can the n=3 shell hold

Answer 7

18

Question 8

how many electrons can the n=4 shell hold

Answer 8

32

Question 9

what is a filled shell

Answer 9

a shell which contains its maximum number of electrons

Question 10

how are electrons arranged

Answer 10

so the lower energy shells are filled first

Question 11

what is ionisation energy

Answer 11

the energy required to remove one electron from each atom in one mole of free gasesous atoms of the element

Question 12

elements with high ionisation enthalpies…

Answer 12

…are difficult to ionise and very unreactive

Question 13

elements with low ionisation enthalpies…

Answer 13

are easy to ionise and very reactive

Question 14

what are shells split into

Answer 14

subshells

Question 15

what are the subshells

Answer 15

s, p, d, f

Question 16

what is the maximum number of electrons that each subshell can hold

Answer 16

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

Question 17

which subshell is in the first energy level and how many electrons does it hold altogether

Answer 17

s subshell (holding only two electrons)

Question 18

which subshell is in the 2nd energy level and how many electrons does it hold altogether

Answer 18

s subshell (two e-)
p subshell (6 e-)
so altogether 8 electrons

Question 19

which subshell is in the 3rd energy level and how many electrons does it hold altogether

Answer 19

s subshell (2 e-)
p subshell (6e-)
d subshell (10e-)
so altogether 18 electrons

Question 20

which subshell is in the 4th energy level and how many electrons does it hold altogether

Answer 20

s subshell (2e-)
p subshell (6e-)
d subshell (10e-)
f subshell (14e-)
so altogether 32 electrons

Question 21

what do subshells within a shell have

Answer 21

different energies

Question 22

are the energies within a subshell fixed

Answer 22

no they can decrease as the charge on the nucleus increases from one element to the next in the periodic table

Question 23

what are the subshells divided into

Answer 23

atomic orbitals

Question 24

where can electron in a given orbital be found

Answer 24

in a particular region of space around the nucleus

Question 25

how many atomic orbitals in an s subshell

Answer 25

1 atomic orbital

Question 26

how many atomic orbitals in a p subshell

Answer 26

3

Question 27

how many atomic orbitals in a d subshell

Answer 27

5

Question 28

how many atomic orbitals in a f subshell

Answer 28

7

Question 29

when do orbitals in the same subshell have the same energy

Answer 29

in an isolated atom

Question 30

why is the probability of finding an electron inside an atom unknown

Answer 30

the position of an electron can't be exactly mapped for an electron in a given orbital

Question 31

how many electrons can be in one atomic orbital

Answer 31

2

Question 32

what do electrons in atoms have

Answer 32

every electron spins at the same rate

Question 33

when do electrons occupy the same orbital

Answer 33

if they have opposite or paired spins

Question 34

what do the box and the two arrow represent

Answer 34

the box is the atomic orbital and the arrows represent electrons

Question 35

what do you need to describe any electron in an atom

Answer 35

the electron shell its in the orbital within the subshell the subshell its spin

Question 36

what kind of shape do atomic orbitals have

Answer 36

a 3d shape

Question 37

what does the 3d shape of an atomic orbital represent

Answer 37

the volume of space where there is a high probability of finding up to 2 electrons

Question 38

what is the electronic configuration

Answer 38

the arrangement of electrons in shells and orbitals

Question 39

how are orbitals filled

Answer 39

in a definite order to produce the lowest energy arrangement as possible

Question 40

in which order are orbitals filled

Answer 40

in order of increasing energy

Question 41

what happens when there is more than one orbital with the same energy

Answer 41

these orbitals are first occupied singly by electrons. this keeps electrons in an atom as far away from each other as possible.

Question 42

when can electrons pair up

Answer 42

when every orbital is singly occupied

Question 43

what kind of spin do electrons in singly occupied orbitals have

Answer 43

a parallel spin to ensure the lowest energy arrangement

Question 44

what does these all represent 1s₂

Answer 44

big 1 = principal quantum number (shell) s = subshell little 2 = no. of electrons

Question 45

why is 4s filled before 3d

Answer 45

it has a lower energy level

Question 46

what is the electronic configuration of vanadium

Answer 46

1) 23e- 2) electrons go into lowest energy shells and subshells 1s2 2s2 2p6 3s2 3p6 3) energy of 4s subshell is lower than the 3d subshell so is filled first 4) remaining e- go into the 3d subshell 1s2 2s2 2p6 3s2 3p6 4s3 3d3

Question 47

electronic configuration of S2-

Answer 47

sulfur - 1s2 2s2 2p6 3s2 3p4 -2 ion so need to add 2 electrons 1s2 2s2 2p6 3s2 3p6

Question 48

electronic configuration of Na+

Answer 48

Na - 1s2 2s2 2p6 3s1 +1 ion so need to take away one e- 1s2 2s2 2p6

Question 49

order of shells and subshells filled

Answer 49

1s 2s 2p 3s 3p 4s 3d 4p 4s is filled before 3d but its written 3d then 4s

Question 50

how can you tell an elements electron configuration from the periodic table

Answer 50

look at the period look at the block count along the block Bromine period 4, p-block, 5 spaces along the block 4p5

Question 51

what is the electronic configuration of chromium

Answer 51

1s2, 2s2, 2p6, 3s2, 3p6, 3d5, 4s1

Question 52

what is the electronic configuration of copper

Answer 52

1s2, 2s2, 2p6, 3s2, 3p6, 3d10, 4s1

Question 53

why dont copper and chromium fill in order

Answer 53

The reason Copper and Chromium have a slighly odd electron configuration is because of stability. By only having 1 electron in the 4s oribtal, Chromium is able to have 1 electron in each of it's 3d orbitals, this configuration is more stable than by having 4s2 3d4