ASChemistryCIEExam Questions1. Atomic Structure1.4 Ionisation Energy

Syllabus Edition

First teaching 2023

First exams 2025

|

Ionisation Energy (CIE AS Chemistry)

Exam Questions

1 hour22 questions

Select a question set to download for
1.4 Ionisation Energy

Select an answer set to view for
1.4 Ionisation Energy

Easy
Medium
Hard
11 mark

Which of the following statements describes first ionisation energy?

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

  • Mg → Mg+ + e-

  • Mg+ → Mg2+ + e-

  • The amount of energy required to remove one mole of electrons from one mole of gaseous ions of an element to form one mole of gaseous 2+ ions

Choose your answer

Did this page help you?

21 mark

Which is the correct equation for the first ionisation energy for magnesium?

  • Mg → Mg+ + e-

  • Mg+ (g) → Mg2+ (g) + e-

  • Mg (g) → Mg+ (g) + e-

  • Mg+ → Mg2+ + e-

Choose your answer

Did this page help you?

31 mark

Why is the second ionisation energy of magnesium higher than the first ionisation energy?

  • Less shielding

  • Ionic radius increases

  • Nuclear charge is increasing

  • Greater attraction between positive nucleus and outer electron

Choose your answer

Did this page help you?

4
Sme Calculator1 mark

The first five ionisation energies of an element are shown below.

What element could this ionisation energy graph belong to?

successive-ionisation-energy

  • N

  • P

  • Al

  • Na

Choose your answer

Did this page help you?

5
Sme Calculator1 mark

Which statement does not explain the increase in ionisation energy across a period?

  • Nuclear charge increases

  • Atomic radius decreases

  • Shielding remains constant

  • Number of electrons increase

Choose your answer

Did this page help you?

11 mark

The second ionisation energy of magnesium is 1451 kJ mol-1. 

Which equation correctly represents this statement?

  • Mg+ (g) → Mg2+ + e-          ΔHӨ = -1451 kJ mol-1

  • Mg+ (g) → Mg2+ + e-          ΔHӨ = +1451 kJ mol-1

  • Mg (g) → Mg2+ + 2e-         ΔHӨ  = +1451 kJ mol-1

  • Mg (g) → Mg+ + e-            ΔHӨ = -1451 kJ mol-1

Choose your answer

Did this page help you?

21 mark

The successive ionisation energies of element X are shown in the table below. Which group of the periodic table does element X belong to?

Ionisation number of X

1

2

3

4

5

6

7

8

Ionisation energy (kJ mol-1)

1314

3388

5301

7469

10989

13327

71337

84080

  • 3

  • 4

  • 5

  • 6

Choose your answer

Did this page help you?

31 mark

X, Y and Z  are consecutive elements in the third Period of the Periodic Table. Element Y has the highest first ionisation energy and also the lowest melting point of these three elements. 

What could be the identities of X, Y and Z?

  • silicon, phosphorus, sulfur 

  • sodium, magnesium, aluminium

  • aluminium, silicon, phosphorus

  • magnesium, aluminium, silicon

Choose your answer

Did this page help you?

41 mark

Successive ionisation energies for an element, Y, are shown in the table below.

Electrons removed

1st

2nd

3rd

4th

5th
Ionisation energy / kJ mol-1

736

1450

7740

10500

13600

What is the most likely formula for the ion of Y?

  • Y+

  • Y2+

  • Y3+

  • Y4+

Choose your answer

Did this page help you?

51 mark

Values for the successive ionisation energies for an unknown element are given in the table below.

First ionisation energy / kJ mol-1

Second ionisation energy / kJ mol-1

Third ionisation energy / kJ mol-1

Fourth ionisation energy / kJ mol-1

420

3600

4400

5900

In which group of the periodic table would the unknown element be found?

  • 1

  • 2

  • 13

  • 14

Choose your answer

Did this page help you?

11 mark

Element X is in period 2 and has the first seven ionisation energies in kJ mol-1 as shown.

1300

3380

5330

7460

11 010

13 320

71 200

What is the electronic configuration of element X?

  • 1s2 2s2 2p4

  • 1s2 2s2 2p2

  • 1s2 2s2 2p3

  • 1s2 2s2 2p6

Choose your answer

Did this page help you?

21 mark

For the successive ionisation energies of oxygen, where would the highest jump be expected to occur?

  • Second ionisation energy

  • First ionisation energy

  • Seventh ionisation energy

  • Sixth ionisation energy

Choose your answer

Did this page help you?

31 mark

The first ionisation energy of beryllium is higher than the first ionisation energy of boron. 

Which statement explains why?

  • Boron has a full outer shell

  • Boron has a larger atomic radius than beryllium

  • Beryllium has a more stable electronic configuration

  • The atomic number of beryllium is higher than boron

Choose your answer

Did this page help you?

41 mark

The electronic configurations of four different atoms are shown. 

Which atom has the highest first ionisation energy?

  • 1s2 2s2 2p6 3s2

  • 1s2 2s2 2p4

  • 1s2 2s2 2p6 

  • 1s2 2s2 

Choose your answer

Did this page help you?

51 mark

The table gives the successive ionisation energies for an element R.

 

1st

2nd

3rd

4th

5th

6th

Ionisation energy / kJ mol-1

950

1800

2700

4800

6000

12300

What could be the oxidation state of element R in its chloride?

  • +1

  • +2

  • +3

  • +4

Choose your answer

Did this page help you?