JEE Main · Chemistry · The d- and f-Block Elements
f-Block Elements: JEE Main previous year questions
25 questions in the 108 JEE Main shifts Lumi analysed, in 6 of 8 years. Pattern: Asked most years. 6 came in 2024–26. Here is how it is asked and which ideas come back.
- Questions
- 25
- in 24 of 108 shifts
- Years asked
- 6/8
- last asked 2026
- Weighted estimate
- 0.2
- model; history: 0.2 a shift on average, typically 0.0–0.3
Key findings
- 01
Asked in 6 of 8 years with analysed shifts and in 24 of 108 shifts: 25 questions, #128 of 196 topics. The years that asked it were 1.2 apart on average.
- 02
52% of its questions since 2020 tested an idea no earlier year had asked; 7 repeated an idea from the year before.
- 03
The most repeated idea is Lanthanide Electronic Configuration, asked 8 times in 8 shifts (2020, 2021, 2022, 2024, 2026), most often as “pairs with equal 4f electron count”.
- 04
JEE Main has asked 11 of the 56 ideas in this topic; 41 have never been asked, directly or inside another question.
- 05
Mostly asked as single correct (72%); 12% need a numerical answer, 32% are easy and 4% hard.
- 06
The skill tested most is conceptual (36%), then recall (32%).
Questions a shift, year by year
Out of the 25 Chemistry questions in a shift. Years differ in how many shifts Lumi analysed, so each year is scaled to one shift.
Raw count: 2017: 0 in 1 shift · 2020: 3 in 12 shifts · 2021: 10 in 24 shifts · 2022: 4 in 24 shifts · 2023: 2 in 12 shifts · 2024: 4 in 18 shifts · 2025: 0 in 8 shifts · 2026: 2 in 9 shifts.
- Up to 2023
- 0.2
- a shift, of 25
- Since 2024
- 0.1
- 0.0
- Usual gap
- 1.2 yrs
- between years asking it
- Shifts with it
- 24/108
- 22% of analysed shifts
How it is asked
Difficulty, format and skill
Across all 25 questions on f-Block Elements since 2017.
Difficulty
QUESTIONS- Easy8 · 32%
- Medium16 · 64%
- Hard1 · 4%
Format
SHARE- Single correct · 18 Q72%
- Numerical value · 3 Q12%
- Other · 2 Q8%
- Match the list · 1 Q4%
- Two statements · 1 Q4%
Skill tested
SHARE- Conceptual · 9 Q36%
- Recall · 8 Q32%
- Application · 6 Q24%
- Calculation · 2 Q8%
Repeats
New idea, or one asked before?
Each column is a year. Blue questions tested an idea no earlier year had asked; navy ones went back to an idea from an earlier year. 2017 is the first year, so everything in it counts as new. Heights are question counts, and Lumi analysed 1 to 24 shifts a year, so compare the split inside a column rather than heights across years.
- Idea asked for the first time
- Idea asked in an earlier year
Coverage of the topic
JEE Main has asked 11 of the 56 ideas in this topic. 41 have never been asked yet.
- Asked directly11 · 20%
- Touched inside another question4 · 7%
- Never asked41 · 73%
Ideas come from Lumi’s JEE syllabus map. A never-asked idea is not a safe skip: across all of JEE Main, 22% of questions since 2024 tested an idea no earlier year had asked.
Drill down
Chapter, idea, question
Every idea JEE Main tested in this topic, with its eight years. Open one to read the questions.
10 ideas inside
Squares are the 8 years with analysed shifts, 2017 to 2026. A number is the questions that year when there is more than one; the shade is scaled to one shift, so a year with more analysed shifts (1 to 24 a year) does not look darker. Share is of the level above.
Ideas
Every idea inside this topic
11 different ideas were tested; 4 came more than once.
pairs with equal 4f electron count
Single correct · 8 shifts · 1 numericalcount correct statements on d- and f-block
Single correct · 4 shiftspair selection among lanthanides
Single correct · 4 shiftsorder/ranking of spin-only magnetic moments
Single correct · 2 shiftscount colourless lanthanoid ions
Numerical value · 1 shift · 1 numericalidentify strong oxidising and reducing lanthanide ions
Single correct · 1 shiftcount 4f electrons in ion
Numerical value · 1 shift · 1 numericalorder/ranking of basicity of hydroxides
Single correct · 1 shifteu2+ reducing nature and configuration
Single correct · 1 shiftidentify lanthanide with given oxidation state and magnetism
Single correct · 1 shiftcomposition of named alloy
Single correct · 1 shift
| Idea | Years asked | Times | Shifts | Format | Numerical |
|---|---|---|---|---|---|
| Lanthanide Electronic Configurationpairs with equal 4f electron count | 8 | 8 | Single correctRecall | 1 | |
| Cerium(IV) as an Oxidizing Agentcount correct statements on d- and f-block | 4 | 4 | Single correctConceptual | – | |
| Lanthanide Oxidation Statespair selection among lanthanides | 4 | 4 | Single correctConceptual | – | |
| Magnetic and Spectral Propertiesorder/ranking of spin-only magnetic moments | 2 | 2 | Single correctApplication | – | |
| Identifying Colorless Lanthanide Ionscount colourless lanthanoid ions | 1 | 1 | Numerical valueApplication | 1 | |
| Europium(II) and Ytterbium(II) as Reducing Agentsidentify strong oxidising and reducing lanthanide ions | 1 | 1 | Single correctConceptual | – | |
| Anomalous Electronic Configuration of Gadoliniumcount 4f electrons in ion | 1 | 1 | Numerical valueApplication | 1 | |
| Basicity Trend of Lanthanide Hydroxidesorder/ranking of basicity of hydroxides | 1 | 1 | Single correctConceptual | – | |
| Europium(II) as a Reducing Agenteu2+ reducing nature and configuration | 1 | 1 | Single correctConceptual | – | |
| Identifying Diamagnetic Lanthanide Ionsidentify lanthanide with given oxidation state and magnetism | 1 | 1 | Single correctRecall | – | |
| Mischmetal Composition and Usescomposition of named alloy | 1 | 1 | Single correctRecall | – |
Times and shifts count every analysed shift. Across JEE Main, 78% of questions since 2024 went back to an idea an earlier year had asked; the rest were new. All repeated ideas
Every question
f-Block Elements questions, year by year
The opening words of each question as it appeared in the official paper, with the idea it tested. Open one for its options and the official answer.
JEE Main 20262 questions in 2 shifts
- 4 Apr, Shift 1Q60The correct statements among the following are, A. Mo(VI) and W(VI) are less stable than Cr(VI). B. and…
Idea: Cerium(IV) as an Oxidizing Agent
HardOther - 4 Apr, Shift 2Q59Pairs of elements with the same number of electrons in their respective 4f orbital are [Atomic number: Eu-63, Gd-64, Dy-66, Ho-67, Tm-69,…
Idea: Lanthanide Electronic Configuration
MediumOther
JEE Main 20244 questions in 4 shifts
- 6 Apr, Shift 1Q69The number of element from the following that do not belong to lanthanoids is Eu, Cm, Er, Tb, Yb and Lu
Idea: Lanthanide Electronic Configuration
EasySingle correct - 9 Apr, Shift 1Q87Number of colourless lanthanoid ions among the following is ________.
Idea: Identifying Colorless Lanthanide Ions
New ideaMediumNumerical value - 27 Jan, Shift 1Q68The electronic configuration for Neodymium is : [Atomic Number for Neodymium 60]
Idea: Lanthanide Electronic Configuration
EasySingle correct - 30 Jan, Shift 1Q67Diamagnetic Lanthanoid ions are :
Idea: Magnetic and Spectral Properties
MediumSingle correct
JEE Main 20232 questions in 2 shifts
- 6 Apr, Shift 1Q70Strong reducing and oxidizing agents among the following, respectively, are
Idea: Europium(II) and Ytterbium(II) as Reducing Agents
New ideaMediumSingle correct - 13 Apr, Shift 1Q70The pair of lanthanides in which both elements have high third - ionization energy is:
Idea: Lanthanide Oxidation States
Asked the year beforeMediumSingle correct
JEE Main 20224 questions in 4 shifts
- 25 Jun, Shift 1Q68Cerium (IV) has a noble gas configuration. Which of the following is **correct** statement about it ?
Idea: Cerium(IV) as an Oxidizing Agent
Asked the year beforeEasySingle correct - 26 Jun, Shift 2Q69The most common oxidation state of Lanthanoid elements is +3. Which of the following is likely to deviate easily from +3 oxidation state?
Idea: Lanthanide Oxidation States
Asked the year beforeMediumSingle correct - 27 Jun, Shift 2Q69The 'f' orbitals are half and completely filled, respectively in lanthanide ions [Given : Atomic no. Eu, 63; Sm, 62; Tm, 69; Tb, 65; Yb,…
Idea: Lanthanide Electronic Configuration
Asked the year beforeMediumSingle correct - 28 Jun, Shift 1Q68Which one of the lanthanoids given below is the most stable in divalent form?
Idea: Lanthanide Oxidation States
Asked the year beforeEasySingle correct
JEE Main 202110 questions in 9 shifts
- 3 Aug, Shift 2Q33The correct order of the basic character for the following metal hydroxides is
Idea: Basicity Trend of Lanthanide Hydroxides
New ideaMediumSingle correct - 3 Aug, Shift 2Q39Which one of the following statements is correct?
Idea: Cerium(IV) as an Oxidizing Agent
New ideaMediumSingle correct - 4 Aug, Shift 1Q40Match List I with List II List I List II A. Gadolinium (At. No. 64) I. B. Holmium (At. No. 67) II. …
Idea: Lanthanide Electronic Configuration
Asked the year beforeMediumMatch the list - 26 Aug, Shift 1Q58The number of 4 electrons in the ground state electronic configuration of is __________. [Atomic number of Gd = 64]
Idea: Anomalous Electronic Configuration of Gadolinium
New ideaMediumNumerical value - 31 Aug, Shift 1Q39Which one of the following lanthanides exhibits oxidation state with diamagnetic nature ? (Given Z for Nd, Yb, La,…
Idea: Identifying Diamagnetic Lanthanide Ions
New ideaMediumSingle correct - 31 Aug, Shift 2Q37The ion is a strong reducing agent in spite of its ground state electronic configuration (outermost) : [Atomic number…
Idea: Europium(II) as a Reducing Agent
New ideaEasySingle correct - 25 Feb, Shift 1Q38Given below are two statements : Statement I : can be used for oxidation of aldehydes and ketones. Statement II : Aqueous…
Idea: Cerium(IV) as an Oxidizing Agent
New ideaMediumTwo statements - 26 Feb, Shift 1Q38Which one of the following lanthanoids does not form ? [M is lanthanoid metal]
Idea: Lanthanide Oxidation States
New ideaMediumSingle correct - 25 Jul, Shift 2Q58Number of electrons present in 4f orbital of ion is ________. (Given Atomic No. of Ho = 67)
Idea: Lanthanide Electronic Configuration
Asked the year beforeEasyNumerical value - 16 Mar, Shift 2Q38Arrange the following metal complex/compounds in the increasing order of spin only magnetic moment. Presume all the three, high spin…
Idea: Magnetic and Spectral Properties
New ideaMediumSingle correct
JEE Main 20203 questions in 3 shifts
- 9 Jan, Shift 1Q36The electronic configurations of bivalent europium and trivalent cerium are : (atomic number : Xe = 54, Ce = 58, Eu = 63)
Idea: Lanthanide Electronic Configuration
New ideaMediumSingle correct - 5 Sep, Shift 1Q37The correct electronic configuration and spin-only magnetic moment (BM) of (), respectively, are :
Idea: Lanthanide Electronic Configuration
New ideaEasySingle correct - 6 Sep, Shift 2Q38Mischmetal is an alloy consisting mainly of :
Idea: Mischmetal Composition and Uses
New ideaEasySingle correct
Questions from the official JEE Main Paper 1 shifts published by NTA (CBSE for 2017). Questions NTA dropped are left out. Topic and idea tags, counts and notes are Lumi’s.