01 Atomic Structure, Set A To print: Ctrl + P, paper A4, margins Default.
Learners' AlleyDesigned by Khow Willard
01

Atomic Structure

Set AFoundations
Name
Time 1 hour
Total 38 marks

A Data Booklet may be used.

A

From the lesson

16 marks
1
Complete the table. The first row is done for you.
speciesprotonsneutronselectrons
23Na111211
23Na+
32S2−
56Fe3+
[3]

Source: Learners' Alley, Atomic Structure slides

2

CommonUnder certain conditions, a beam of 1H+ is deflected by +12°. Under the same conditions, calculate the angle of deflection of

(a)
2H+
[1]
(b)
4He2+
[1]
(c)
16O2−
[1]

Source: Learners' Alley, Atomic Structure slides

3
Magnesium is 79.0% 24Mg, x% 25Mg and the rest 26Mg. The Ar of magnesium is 24.32. Calculate x.
[2]

Source: Learners' Alley, Atomic Structure slides

4
ChallengeChlorine is 75% 35Cl and 25% 37Cl. Each Cl2 molecule contains two Cl atoms picked at random. Calculate the relative abundances of the three kinds of Cl2 molecule, of masses 70, 72 and 74.
[2]

Source: Learners' Alley, Atomic Structure slides

5

Write the full electronic configurations of

(a)
K (proton number 19)
[1]
(b)
Mn (proton number 25)
[1]
(c)
Br (proton number 35)
[1]

Source: Learners' Alley, Atomic Structure slides

6
CommonElement Y is in Period 3. Its first five ionisation energies, in kJ mol−1, are

578   1817   2745   11 577   14 842

State the Group of Y and identify Y.
[1]

Source: Learners' Alley, Atomic Structure slides

7
ChallengeElement Z has these successive ionisation energies, in kJ mol−1:

496   4562   6912   9543

State the Group of Z, and explain why its second ionisation energy is so much larger than its first.
[2]

Source: Learners' Alley, Atomic Structure slides

B

Practice

22 marks
8

CommonWhat do the ions 18O2− and 19F− have in common?

AThey have more electrons than neutrons.
BThey have 10 neutrons in their nuclei.
CThey have an outer electronic configuration of 3s2 3p6.
DThey contain the same number of nucleons in their nuclei.
Answer [1]

Source: 2024 RI J2 Prelim P1 Q3

9

Which of the following species has no unpaired electrons?

AFe3+
BGe+
CCu+
DTi3+
Answer [1]

Source: RVHS 2017 Promo, via EJC 2022 Atomic Structure Topical Revision, Q7

10

Which particle would, on losing an electron, have a half-filled set of p orbitals?

AC−
BN−
CO+
DP+
Answer [1]

Source: IJC 2017 Promo, via EJC 2022 Atomic Structure Topical Revision, Q8

11
Hydrogen exists as the isotopes 1H, 2H and 3H. Complete the table.
speciesnumber of protonsnumber of neutronsnumber of electrons
2H
1H2+
3H3+
[3]

Source: 2024 NYJC J2 Prelim P2 Q1(c)

12

Magma, the molten rock under the Earth's surface, is rich in oxygen and silicon.

(a)
State the electronic configuration of an atom of silicon.
[1]
(b)
Describe one similarity and one difference between a 3s orbital and a 3p orbital.
[2]
(c)
Describe one difference between a 2p orbital and a 3p orbital.
[1]

Source: 2022 HCI J1 Promo P3 Q1(a)

13

CommonIons of 28Si+ and X+ are passed through the same electric field. Their angles of deflection are 5.6° and 2.0° respectively.

(a)
Deduce, by calculation, the identity of X.
[2]
(b)
Suggest why another beam is detected with an angle of deflection of 1.9°.
[1]

Source: 2024 CJC J2 Prelim P2 Q1(d)

14

CommonThis question is about the first ionisation energies of the Period 3 elements, sodium to argon.

(a)
Explain the general increase in first ionisation energy from sodium to argon.
[2]
(b)
Explain the fall in first ionisation energy between magnesium and aluminium.
[2]
(c)
Explain the fall in first ionisation energy between phosphorus and sulfur.
[2]

Source: EJC 2022 JC1 Atomic Structure Tutorial, A3(b) to (d)

15

ChallengeBoron and its compounds have many uses in industry.

(a)
Write an equation to represent the fourth ionisation energy of boron.
[1]
(b)
Explain why the fourth ionisation energy of boron is much higher than that of carbon.
[2]

Source: 2024 RI J2 Prelim P2 Q1(a)