AQA A-Level Chemistry AS Paper 1, June 2022: Question 20

1 mark · Easy difficulty · Multiple Choice

Identify which block of the Periodic Table contains the element samarium (Sm).

Practise this question

Question

Multiple choice question 20: 'Which block in the Periodic Table contains the element samarium (Sm)?' Option A is d block, Option B is f block, Option C is p block, Option D is s block.
Question text

20 Which block in the Periodic Table contains the element samarium (Sm)?

[1 mark]

A d block

B f block

C p block

D s block

Mark scheme

Show the mark scheme Mark scheme table row for question 20 showing the correct answer as B (AO1) with 1 mark, corresponding to 'f block'.

20 B (AO1) 1 f block

How to answer it

Periodic Table Blocks: Identifying Element Blocks

📌 What this question tests

This question assesses basic recall and navigation of the Periodic Table Data Sheet provided in A-Level exams. Specifically, it tests your ability to identify the blocks (s, p, d, f) and locate unfamiliar elements like lanthanides (e.g. samarium, atomic number 62) within the f-block.

Question 20 • Multiple Choice [1 Mark]

Locating Samarium (Sm) in the Periodic Table

Identifying the sub-shell block for element Z = 62

✅ Correct Answer

B: f block

Mark Scheme Breakdown:
• Award 1 mark for selecting option B (AO1 - recall).

💡 Key Knowledge

  • Block definition: An element's block corresponds to the sub-shell containing its highest-energy electron.
  • s-block: Groups 1 and 2 (plus He and H).
  • p-block: Groups 13 to 18 (Group 3 to Group 0/8).
  • d-block: Transition metals (Sc to Zn group).
  • f-block: Lanthanides (La/Ce to Lu, atomic numbers 57/58–71) and Actinides (Ac/Th to Lr, atomic numbers 89/90–103), located in the two detached rows at the bottom of the table.

🧠 Exam Technique

  • Always open your Data Booklet: Do not guess unfamiliar element names. Flip directly to the Periodic Table.
  • Find atomic number (Z): Samarium has atomic number Z = 62 and symbol Sm .
  • Inspect location: Z = 62 sits between Cerium (58) and Lutetium (71) in the top floating row at the bottom (Lanthanoids). This is definitively the f-block.
  • This saves time: answering this takes less than 15 seconds, leaving valuable minutes for extended calculation and organic synthesis questions.

❌ Common Errors & Misconceptions

  • Confusing d-block with f-block: Assuming any obscure metal must be a standard transition metal in the d-block.
  • Misreading the symbol: Mistaking Samarium ( Sm ) for Scandium ( Sc , d-block, Z = 21) or Tin ( Sn , p-block, Z = 50).
  • Not looking at the bottom rows: Forgetting that the two rows positioned beneath the main body of the Periodic Table represent the filling of the 4f and 5f sub-shells.

Topics

Inorganic Chemistry · 3.2.1 Periodicity

Question and mark scheme from the AQA A-Level Chemistry examination, AS Paper 1, June 2022. QuestionVault is an independent revision resource; questions remain the copyright of the awarding body.