Electronic Structure

Question 1

What is the name given to the shell and its distance from the nucleus?

Answer 1

Principal quantum number.

Question 2

What is the principle quantum number of the first shell?

Answer 2

1

Question 3

What is the principle quantum number of the second shell?

Answer 3

2

Question 4

What is the principle quantum number of the third shell?

Answer 4

3

Question 5

What gives a shell a larger principal quantum number?

Answer 5

The further the shell is from the nucleus.

Question 6

What sub shell does the 1st shell contain?

Answer 6

1s

Question 7

What sub shells does the 2nd shell contain?

Answer 7

2s and 2p

Question 8

What sub shells does the 3rd shell contain?

Answer 8

3s, 3p and 3d.

Question 9

What sub shell does the 4th shell contain?

Answer 9

4s, 4p, 4d and 4f.

Question 10

What is the number or orbitals and maximum electrons for the s sub-shell?

Answer 10

Number of orbitals- 1

Maximum electrons- 2

Question 11

What is the number or orbitals and maximum electrons for the p sub-shell?

Answer 11

Number of orbitals- 3

Maximum electrons- 6

Question 12

What is the number or orbitals and maximum electrons for the d sub-shell?

Answer 12

Number of orbitals- 5

Maximum electrons- 10

Question 13

What is the number or orbitals and maximum electrons for the f sub-shell?

Answer 13

Number of orbitals- 7

Maximum electrons- 14

Question 14

What is the s orbital shape?

Answer 14

Spherical

Question 15

What is the p orbital shape?

Answer 15

Dumbell-shaped.

Question 16

What 3 ways can you show electron configuration?

Answer 16

Sub shell notation
Arrows in boxes
Energy level diagrams

Question 17

Which electron shells are filled up first?

Answer 17

Electrons fill orbitals singly before they start sharing, so the two electrons in the 2p sub-shells should be in separate orbitals.

Question 18

Which one of the first, second or third ionisations of thallium produces an ion with the electron configuration [Xe] 5d10 6s1?

Answer 18

Second

Question 19

State the general trend in first ionisation energies from carbon to neon.
Deduce the element that deviates from this trend and explain why this element deviates from the trend.

Answer 19

Increase
Oxygen / O
Paired electrons in a (2)p orbital

Question 20

Write an equation, including state symbols, for the reaction that occurs when the first ionisation energy of carbon is measured.

Answer 20

C(g) → C+(g) + e(-)

Question 21

Explain why the second ionisation energy of carbon is higher than the first ionisation energy of carbon.

Answer 21

(More energy to) remove an electron from a (more) positive ion.

Question 22

Deduce the element in Period 2, from lithium to neon, that has the highest second ionisation energy.

Answer 22

Lithium

Question 23

Explain the trend of increase across Period 2 of ionisation energy.

Answer 23

• Number of protons increases.
• Outermost electrons are in the same shell
• Greater nuclear attraction (on outermost electrons)

Question 24

The first ionisation energy of oxygen is less than the first ionisation energy of fluorine.

Answer 24

• O has one less proton and so a smaller nuclear charge.
• Atomic radius of O is larger.
• Outer electrons are attracted less strongly (to the nucleus) in O.

Question 25

When oxygen reacts with metals it forms oxide ions. Write the electron configurations, in terms of sub-shells, of an oxygen atom and an oxide ion. Hence, explain why this reaction of oxygen is typical of a non-metal.

Answer 25

1s2 2s2 2p4 and 1s2 2s2 2p6 | In the reaction oxygen has formed a negative ion (by gaining two electrons.

Question 26

Complete the electron configuration of a magnesium atom.

Answer 26

1s2 2s2 2p6 3s2

Question 27

Write an equation to represent the second ionisation energy of magnesium. Include state symbols.

Answer 27

Mg+(g) -> Mg2+(g) + e–

Question 28

Explain why there is an increase in first ionisation energy between F and Ne.

Answer 28

Ne has one more proton Outermost electrons are in the same shell Greater nuclear attraction on outermost electrons

Question 29

Explain why there is a decrease in first ionisation energy between Ne and Na.

Answer 29

Na has one more shell Outermost electron experiences greater shielding Less nuclear attraction on outermost electrons

Question 30

Why is the first ionisation energy of strontium larger than the first ionisation energy of rubidium?

Answer 30

Sr has one more proton and therefore greater nuclear charge. Atomic radius of Sr is smaller. Sr has greater nuclear attraction on outer electrons / outer shell.

Question 31

Why is the second ionisation energy of rubidium larger than the second ionisation energy of strontium?

Answer 31

2nd IE of Rb involves removing electron from shell. | Stronger nuclear attraction on outermost electron of Rb.

Question 32

Explain why xenon has a lower first ionisation energy than neon.

Answer 32

Xe has a bigger atomic radius and more shielding.

Question 33

What is meant by an orbital?

Answer 33

A region (within an atom) that can hold up to two electrons with opposite spin.

Question 34

State the total number of electrons occupying the p orbitals in one chlorine atom.

Answer 34

11

Question 35

How many electrons are there in one ion of Ca2+?

Answer 35

18

Question 36

Write the equation that represents the third ionisation energy of Al.

Answer 36

Al2+(g) -> Al3+(g) + e–

Question 37

Define successive ionisation energy

Answer 37

A measure of the energy required to remove each electron in turn.