| 2,242,985 | Elements of the Periodic Table |
| 1,097,553 | Planets of the Solar System Quiz |
| 225,808 | Signs of the Zodiac Quiz |
| 215,738 | Songs with Body Parts in the Title |
| 205,592 | Three Letter Body Parts |
| 197,266 | Elements by Symbol |
| 188,768 | Periodic Table Quiz - First 20 Elements |
| 176,344 | Word Scramble - Body Parts |
| 166,032 | Science General Knowledge #1 |
| 156,866 | International Scientific Units |
| 151,850 | Most Common Elements in the Human Body |
| 147,555 | Countries with the Most Forest |
| 145,962 | Body Part Words |
| 137,279 | Largest Objects in the Solar System |
| 131,763 | Element... or Pokémon? |
| 131,198 | Elements - Sudden Death |
| 129,178 | Human Body A-Z |
| 124,180 | Medical Conditions Quiz |
| 123,308 | Body Part Cliches |
| 119,278 | Organs of the Human Body (with map) |
| 118,845 | Science General Knowledge #2 |
| 109,715 | Countries with the Highest Carbon Dioxide Emissions |
| 108,743 | Science General Knowledge #3 |
| 105,422 | Countries with Glaciers |
| 104,699 | Speed Symbol by Element |
| 102,919 | Periodic Table Elements A-Z |
| 97,155 | "Ologies" Quiz |
| 96,849 | Medical Acronyms |
| 94,232 | Chemical Elements with Short Names |
| 93,441 | Metals of Antiquity |
| 93,096 | Random Symbol to Element |
| 91,775 | Medical Specialties |
| 91,428 | Click the Planet |
| 88,182 | One-Syllable Human Body Parts |
| 86,562 | Science Multiple Choice #1 |
| 82,613 | Astronomy Quiz |
| 82,085 | Tropical Rainforest Countries |
| 81,682 | Elements with One-Letter Symbols |
| 80,694 | Birthstones by Month |
| 80,572 | Major Taxonomic Ranks |
| 80,466 | Click the Chemical Element |
| 78,468 | Scientific Names |
| 78,182 | Noble Gases |
| 76,761 | Name the Virus |
| 75,333 | Most Forested European Countries |
| 72,274 | Periodic Table Symbols |
| 71,846 | Science Vocabulary #1 |
| 70,707 | Periodic Table Elements Mentioned in the Bible |
| 70,054 | Name a Valid Element |
| 69,965 | Elements by Picture |
| 66,536 | Worst Plastic Polluting Countries |
| 65,206 | Least-Forested Countries |
| 64,977 | Dumb it Down Doc |
| 64,715 | Least Forested Countries in Asia |
| 64,657 | Countries Reducing Carbon Dioxide Emissions the Most |
| 64,592 | Elements that are Gases at Room Temperature |
| 63,446 | Top 10 Most Forested Countries in Asia |
| 63,281 | Body Parts - Sudden Death #1 |
| 62,778 | Electromagnetic Spectrum |
| 62,518 | Periodic Table Elements by Clue #1 |
| 59,989 | Top 10 Solar Power Countries |
| 59,822 | Animal Anatomy Quiz |
| 59,654 | Science Vocabulary #2 |
| 59,107 | Medical Vocabulary |
| 57,789 | Diseases and Medical Conditions A-Z |
| 56,884 | First Names of Scientists |
| 56,846 | Planets By Picture Quiz |
| 55,649 | Countries with Tropical Rainforest and Glaciers |
| 55,586 | One Letter Periodic Table Symbols - Sudden Death |
| 55,490 | Countries with the Most Forest A-Z |
| 55,030 | Answers are Elements #2 |
| 54,895 | Word Chain - Science |
| 54,019 | Least Forested European Countries |
| 53,987 | Things Named For People #3 - Science |
| 53,696 | Category Elimination - Elements |
| 53,575 | Planets - Multiple Choice |
| 52,830 | Answers are Elements #1 |
| 52,295 | Elemental Words |
| 51,998 | Science Vocabulary #3 |
| 50,728 | Bones - Sudden Death |
| 49,154 | Countries by Carbon Dioxide Emissions per Capita |
| 48,328 | Groups of Two - Science |
| 48,199 | Most Guessed Elements on JetPunk |
| 46,663 | Solar System Trivia |
| 46,521 | Top 10 Least-Forested U.S. States |
| 46,499 | Animals by Skeleton Image |
| 45,639 | Top 10 Most-Forested U.S. States |
| 45,295 | Countries with the Most Malaria Deaths |
| 44,987 | Name the Constellations |
| 44,449 | Countries with the Most HIV |
| 43,498 | Fish... or Not a Fish? |
| 42,650 | Famous Scientists |
| 42,451 | Bones of the Human Body |
| 42,276 | First 30 Elements Periodic Table |
| 42,071 | Citrus Fruits |
| 41,668 | Countries that Desalinate the Most Water |
| 40,961 | Name a Valid Answer - Science |
| 40,307 | Science True or False |
| 38,707 | Diseases: Virus... or Bacteria? |
| 38,059 | Astronomy Decoder |
| 37,815 | Countries with the Highest Percentage of Forest |
| 36,582 | Science Multiple Choice #2 |
| 36,473 | Astronomy True or False |
| 36,430 | First Twenty Elements - Sudden Death |
| 36,147 | Northernmost Countries Without Glaciers |
| 35,939 | Name the Constellations - With a Map |
| 35,398 | Largest Countries Without Glaciers |
| 35,283 | Body Parts in History and Culture |
| 34,684 | The Sun Quiz |
| 34,629 | Countries with the Most Mangroves |
| 34,618 | Science Multiple Choice #3 |
| 33,910 | Bones in the Human Body |
| 32,010 | Lightest Chemical Elements A-Z |
| 31,658 | Most Common Body Part Words |
| 29,325 | Rocks and Minerals Picture Quiz |
| 28,772 | Science Decoder |
| 28,324 | Brightest Natural Objects in the Sky |
| 28,288 | Animals - Taxonomy to Common Name |
| 26,834 | Environmental Issues |
| 26,391 | U.S. States with the Most Drug Overdose Deaths |
| 25,821 | Top 10 U.S. States by Solar Power |
| 25,348 | Body Parts - No Vowels |
| 25,304 | U.S. States with Glaciers |
| 24,707 | Elements Named for Countries |
| 21,197 | First 40 Elements |
| 20,812 | 16 Questions that Prove that Physics Makes No Sense |
| 19,644 | Click Every Chemical Symbol |
| 18,667 | The Mars Quiz |
| 18,392 | Albert Einstein Trivia |
| 17,847 | Elements Whose First Letter Doesn't Match the Symbol |
| 17,258 | Countries with the Most Sunlight Per Square Meter |
| 16,461 | The Jupiter Quiz |
| 15,523 | First 50 Elements |
| 14,715 | Recommended Childhood Vaccines for Americans |
| 14,482 | The Voyage of Darwin - Animated Map Quiz |
| 14,012 | The Diseases They Had |
| 13,917 | Elements of the Periodic Table by Symbol |
| 13,751 | Name the Metal Alloy |
| 13,062 | Periodic Table Symbols - Sudden Death |
| 12,714 | Body Parts - Sudden Death #2 |
| 12,561 | Medicine and Anatomy by Letter - A |
| 12,512 | Famous Effects |
| 12,182 | Periodic Table Elements by Clue #2 |
| 11,556 | The Saturn Quiz |
| 11,555 | A Quiz About Diamonds |
| 11,357 | Random Elements on the Periodic Table |
| 10,949 | Amino Acids to 1 Letter Code |
| 10,605 | Random Element to Atomic Number |
| 10,294 | Physics Equations |
| 9,857 | The Pluto Quiz |
| 9,524 | First 60 Elements |
| 9,115 | Simple Machines Quiz |
| 8,973 | Periodic table challenge - IN ORDER! |
| 8,517 | Astronomy & Space |
| 8,209 | Periodic Table of Elements - in Order |
| 8,181 | Medication... or Pokémon? |
| 7,747 | The Elements of the Periodic Table |
| 7,639 | All Elements of The Periodic Table - Sudden Death (Hard) |
| 7,592 | Name Elements Containing Each Letter A-Z |
| 7,319 | Organs of the Body |
| 7,320 | Click the Chemical Element #2 |
| 6,925 | The Venus Quiz |
| 6,835 | Science General Knowledge #1 |
| 6,826 | Constellation Map |
| 6,782 | Countries That Discovered the Elements of the Periodic Table |
| 6,700 | First 28 Countries of Wuhan Coronavirus COVID-19 Outbreak |
| 6,283 | Moons of the Solar System |
| 6,245 | Random Constellations on a Map |
| 6,069 | Medicine and Anatomy by Letter - B |
| 6,044 | Scientific Groups of Things #1 |
| 5,768 | Human anatomy for dummies |
| 5,754 | Human Skeleton |
| 5,754 | Name the Planets* |
| 5,639 | Physics General Knowledge |
| 5,629 | Medicine and Anatomy by Letter - C |
| 5,519 | Elements of The Periodic Table - Sudden Death |
| 5,443 | Human Biology Multiple Choice Quiz #3 |
| 5,435 | Causes of Death on Mount Everest |
| 5,213 | Muscles of the human body - with a map |
| 5,145 | Astronomy General Knowledge Quiz #1 |
| 4,999 | Medicine and Anatomy by Letter - D |
| 4,969 | Crossword - Elements |
| 4,805 | Click the Element on the Periodic Table |
| 4,774 | The 8 Planets of Solar System - Map Quiz |
| 4,566 | Medicine and Anatomy by Letter - F |
| 4,556 | Space and Astronomy General Knowledge |
| 4,558 | Click on the Fish (Sudden Death) |
| 4,470 | Random Sequential Elements on the Periodic Table |
| 4,438 | Biology Vocabulary |
| 4,427 | Physics A-Z |
| 4,285 | Periodic Table Quiz by Borders in 60 Seconds |
| 4,167 | Muscles of the Human Body |
| 4,146 | Seven Strong Acids Quiz |
| 4,113 | Amino Acid Structures |
| 4,052 | Musical Movies - Sudden Death #2 |
| 4,045 | Medicine and Anatomy by Letter - E |
| 3,979 | Anatomy of the Human Eye Map Quiz |
| 3,970 | First 36 Periodic Table Elements |
| 3,953 | Name the 20 Amino Acids |