KRILLIONIOSearch

Search Krillion

Prompts, tools and daily editions. Answers stay hidden.

↑↓ to select ↵ to open Esc to closeFull prompt search →

Science

Name an element with atomic number 30 or below.

The first 30 elements. Element names and chemical symbols both count.

Treat the atomic-number cutoff and accepted spelling as two separate checks.

Read the rule before answering

Use atomic number, not atomic mass. Both endpoints, 1 and 30, are included. A listed chemical symbol and its full element name identify the same answer.

Practice this question without a timer →

Six untimed questions, starting with this one.

Check an answer here

Check this question’s accepted set without submitting to a game or opening the full answer list.

Only your submitted spelling will be checked. Other answers stay hidden.

Read the lesson — reveals answers & strategy
Pixel art of a chemistry reference book with element tiles and a model.

Understand the boundary

Atomic number determines membership, not atomic mass or the order in which you learned the elements. The range includes both hydrogen at 1 and zinc at 30. Names and listed chemical symbols refer to the same canonical answers.

Verify the facts: IUPAC · Periodic table ↗

Choose an answer for your goal

Scandium earns 96 points and accepts Sc; vanadium earns 94 and accepts V. A verified symbol can save typing time without lowering the score. Do not construct a symbol from a name’s first letter: sodium uses Na, and the checker does not accept invented abbreviations. Practice the exact symbol before relying on it in a timed round.

Worked examples — reveals answers
Sc · Accepted
The listed symbol for scandium, atomic number 21.
Aluminum · Accepted
An explicit spelling alias for aluminium in this catalog.
Gallium · Outside this set
Atomic number 31 lies just beyond the inclusive cutoff.

Practice the distinction

Check a name, then its listed symbol, and compare the points. Next switch to the first-ten-elements question. A spelling that worked here can fail there because the atomic-number boundary changed.

Try it in the checker ↑
Give me a hint — no answer revealed

Start with the full category, then apply the exact boundary: The first 30 elements. Element names and chemical symbols both count. You only need one qualifying answer. A longer name is not automatically rarer.

Reveal a verified practice pick
CobaltCobalt (Co) has atomic number 27 on the IUPAC periodic table.
83

This pick belongs to the selected question’s answer set. Points are a fixed knowledge rating.

Reveal a fast high-scoring answer

Shortest accepted input at 65+ points

V

Vanadium · 94 points · 1 characters

Vanadium (V) has atomic number 23 on the IUPAC periodic table.

Highest fixed score

Scandium

96 points · Shortest accepted spelling: Sc

These are editorial points, separate from real player choice counts.

Reveal all 30 practice answers

Filter by a name or listed alias. Scores are fixed knowledge ratings.

30 accepted answers

ScandiumScandium (Sc) has atomic number 21 on the IUPAC periodic table.Aliases: ScShortest accepted input: Sc · 2 characters
96 points
VanadiumVanadium (V) has atomic number 23 on the IUPAC periodic table.Aliases: VShortest accepted input: V · 1 characters
94 points
ManganeseManganese (Mn) has atomic number 25 on the IUPAC periodic table.Aliases: MnShortest accepted input: Mn · 2 characters
89 points
BerylliumBeryllium (Be) has atomic number 4 on the IUPAC periodic table.Aliases: BeShortest accepted input: Be · 2 characters
88 points
CobaltCobalt (Co) has atomic number 27 on the IUPAC periodic table.Aliases: CoShortest accepted input: Co · 2 characters
83 points
ArgonArgon (Ar) has atomic number 18 on the IUPAC periodic table.Aliases: ArShortest accepted input: Ar · 2 characters
78 points
ChromiumChromium (Cr) has atomic number 24 on the IUPAC periodic table.Aliases: CrShortest accepted input: Cr · 2 characters
77 points
FluorineFluorine (F) has atomic number 9 on the IUPAC periodic table.Aliases: FShortest accepted input: F · 1 characters
74 points
BoronBoron (B) has atomic number 5 on the IUPAC periodic table.Aliases: BShortest accepted input: B · 1 characters
72 points
PhosphorusPhosphorus (P) has atomic number 15 on the IUPAC periodic table.Aliases: PShortest accepted input: P · 1 characters
68 points
NickelNickel (Ni) has atomic number 28 on the IUPAC periodic table.Aliases: NiShortest accepted input: Ni · 2 characters
64 points
SulfurSulfur (S) has atomic number 16 on the IUPAC periodic table.Aliases: S · SulphurShortest accepted input: S · 1 characters
60 points
TitaniumTitanium (Ti) has atomic number 22 on the IUPAC periodic table.Aliases: TiShortest accepted input: Ti · 2 characters
59 points
ZincZinc (Zn) has atomic number 30 on the IUPAC periodic table.Aliases: ZnShortest accepted input: Zn · 2 characters
57 points
MagnesiumMagnesium (Mg) has atomic number 12 on the IUPAC periodic table.Aliases: MgShortest accepted input: Mg · 2 characters
54 points
PotassiumPotassium (K) has atomic number 19 on the IUPAC periodic table.Aliases: KShortest accepted input: K · 1 characters
52 points
ChlorineChlorine (Cl) has atomic number 17 on the IUPAC periodic table.Aliases: ClShortest accepted input: Cl · 2 characters
50 points
SiliconSilicon (Si) has atomic number 14 on the IUPAC periodic table.Aliases: SiShortest accepted input: Si · 2 characters
49 points
LithiumLithium (Li) has atomic number 3 on the IUPAC periodic table.Aliases: LiShortest accepted input: Li · 2 characters
48 points
NeonNeon (Ne) has atomic number 10 on the IUPAC periodic table.Aliases: NeShortest accepted input: Ne · 2 characters
47 points
SodiumSodium (Na) has atomic number 11 on the IUPAC periodic table.Aliases: NaShortest accepted input: Na · 2 characters
42 points
CalciumCalcium (Ca) has atomic number 20 on the IUPAC periodic table.Aliases: CaShortest accepted input: Ca · 2 characters
39 points
NitrogenNitrogen (N) has atomic number 7 on the IUPAC periodic table.Aliases: NShortest accepted input: N · 1 characters
38 points
AluminiumAluminium (Al) has atomic number 13 on the IUPAC periodic table.Aliases: Al · AluminumShortest accepted input: Al · 2 characters
35 points
HeliumHelium (He) has atomic number 2 on the IUPAC periodic table.Aliases: HeShortest accepted input: He · 2 characters
26 points
CopperCopper (Cu) has atomic number 29 on the IUPAC periodic table.Aliases: CuShortest accepted input: Cu · 2 characters
25 points
IronIron (Fe) has atomic number 26 on the IUPAC periodic table.Aliases: FeShortest accepted input: Fe · 2 characters
20 points
CarbonCarbon (C) has atomic number 6 on the IUPAC periodic table.Aliases: CShortest accepted input: C · 1 characters
18 points
HydrogenHydrogen (H) has atomic number 1 on the IUPAC periodic table.Aliases: HShortest accepted input: H · 1 characters
15 points
OxygenOxygen (O) has atomic number 8 on the IUPAC periodic table.Aliases: OShortest accepted input: O · 1 characters
12 points

What players actually choose

– UTC · 670 recorded daily rounds. Source: Krillionio daily submissions. Skips and timeouts are included in the denominator; practice and Battle are excluded.

529 / 670 rounds ended with an accepted answer (79.0%). Average: 37.2 fixed points.

Compare observed choices — reveals answers
  1. Chlorine 6 / 670 rounds · 0.9% chosen · 50 fixed points · 99.1 player rarity index
  2. Phosphorus 6 / 670 rounds · 0.9% chosen · 68 fixed points · 99.1 player rarity index
  3. Scandium 8 / 670 rounds · 1.2% chosen · 96 fixed points · 98.8 player rarity index
  4. Chromium 9 / 670 rounds · 1.3% chosen · 77 fixed points · 98.7 player rarity index
  5. Aluminium 11 / 670 rounds · 1.6% chosen · 35 fixed points · 98.4 player rarity index
  6. Magnesium 11 / 670 rounds · 1.6% chosen · 54 fixed points · 98.4 player rarity index
  7. Fluorine 12 / 670 rounds · 1.8% chosen · 74 fixed points · 98.2 player rarity index
  8. Vanadium 12 / 670 rounds · 1.8% chosen · 94 fixed points · 98.2 player rarity index
  9. Copper 13 / 670 rounds · 1.9% chosen · 25 fixed points · 98.1 player rarity index
  10. Beryllium 14 / 670 rounds · 2.1% chosen · 88 fixed points · 97.9 player rarity index
  11. Manganese 14 / 670 rounds · 2.1% chosen · 89 fixed points · 97.9 player rarity index
  12. Nitrogen 14 / 670 rounds · 2.1% chosen · 38 fixed points · 97.9 player rarity index
  13. Zinc 17 / 670 rounds · 2.5% chosen · 57 fixed points · 97.5 player rarity index
  14. Calcium 18 / 670 rounds · 2.7% chosen · 39 fixed points · 97.3 player rarity index
  15. Lithium 18 / 670 rounds · 2.7% chosen · 48 fixed points · 97.3 player rarity index
  16. Sodium 18 / 670 rounds · 2.7% chosen · 42 fixed points · 97.3 player rarity index
  17. Oxygen 24 / 670 rounds · 3.6% chosen · 12 fixed points · 96.4 player rarity index
  18. Potassium 26 / 670 rounds · 3.9% chosen · 52 fixed points · 96.1 player rarity index
  19. Neon 32 / 670 rounds · 4.8% chosen · 47 fixed points · 95.2 player rarity index
  20. Iron 33 / 670 rounds · 4.9% chosen · 20 fixed points · 95.1 player rarity index
  21. Argon 37 / 670 rounds · 5.5% chosen · 78 fixed points · 94.5 player rarity index
  22. Hydrogen 37 / 670 rounds · 5.5% chosen · 15 fixed points · 94.5 player rarity index
  23. Carbon 38 / 670 rounds · 5.7% chosen · 18 fixed points · 94.3 player rarity index
  24. Helium 43 / 670 rounds · 6.4% chosen · 26 fixed points · 93.6 player rarity index
  25. Boron 46 / 670 rounds · 6.9% chosen · 72 fixed points · 93.1 player rarity index

Question quality signals

These measurements cover completed daily rounds recorded with timing and rejection details. Older rounds without those fields are excluded. At least 20 measured rounds are required per question.

  1. Name an element with atomic number 30 or below. Frequent unlisted inputs 151/183 accepted · 29/183 timed out · 3/183 skipped. 66 rounds had an unlisted input (98 attempts); 41 of those rounds later accepted an answer. Check the rule and answer set →

Review thresholds: below 20% accepted, at least 40% timed out, or at least 30% of rounds with an unlisted input. These flags suggest checking the wording and answer coverage; they do not prove an answer is wrong or change points automatically. Abandoned rounds and practice attempts are not included.

How these statistics work
What is counted
Source: Krillionio daily submissions. Skips and timeouts count as rounds; practice and Battle are excluded.
When comparisons appear
A question needs at least 20 recorded rounds. An answer also needs at least 5 recorded choices within that question.
What the data can tell you
These anonymous browser records are not verified unique people or a representative survey. The player rarity index does not change game points or predict the original Krillion game. Raw submissions stay private.
Read method & limitations View aggregate data (JSON)
Rule examples & common mix-ups — may reveal answers
  • Both the element’s group and the atomic-number limit must fit. A chemical symbol is an accepted spelling, not a way to bypass either restriction.

These notes explain the question boundary; they are not a ranking of player mistakes.

Why these answers qualify

Each entry belongs to the bounded set defined by the prompt. The named source supports the underlying facts; our editorial scoring is a separate layer.

Source: IUPAC · Periodic table ↗

Reference version: 2026-09-13. See our answer policy for how we handle aliases and omissions.

Check my answer →Find a rare answer →More Science practice →