| 2,242,902 | Elements of the Periodic Table |
| 1,097,524 | Planets of the Solar System Quiz |
| 225,799 | Signs of the Zodiac Quiz |
| 215,734 | Songs with Body Parts in the Title |
| 205,592 | Three Letter Body Parts |
| 197,260 | Elements by Symbol |
| 188,766 | Periodic Table Quiz - First 20 Elements |
| 176,343 | Word Scramble - Body Parts |
| 166,029 | Science General Knowledge #1 |
| 156,859 | International Scientific Units |
| 151,847 | Most Common Elements in the Human Body |
| 147,554 | Countries with the Most Forest |
| 145,959 | Body Part Words |
| 137,276 | Largest Objects in the Solar System |
| 131,760 | Element... or Pokémon? |
| 131,185 | Elements - Sudden Death |
| 129,176 | Human Body A-Z |
| 124,176 | Medical Conditions Quiz |
| 123,307 | Body Part Cliches |
| 119,275 | Organs of the Human Body (with map) |
| 118,840 | Science General Knowledge #2 |
| 109,714 | Countries with the Highest Carbon Dioxide Emissions |
| 108,734 | Science General Knowledge #3 |
| 105,422 | Countries with Glaciers |
| 104,692 | Speed Symbol by Element |
| 102,916 | Periodic Table Elements A-Z |
| 97,150 | "Ologies" Quiz |
| 96,848 | Medical Acronyms |
| 94,230 | Chemical Elements with Short Names |
| 93,440 | Metals of Antiquity |
| 93,094 | Random Symbol to Element |
| 91,773 | Medical Specialties |
| 91,427 | Click the Planet |
| 88,177 | One-Syllable Human Body Parts |
| 86,561 | Science Multiple Choice #1 |
| 82,611 | Astronomy Quiz |
| 82,083 | Tropical Rainforest Countries |
| 81,677 | Elements with One-Letter Symbols |
| 80,694 | Birthstones by Month |
| 80,568 | Major Taxonomic Ranks |
| 80,460 | Click the Chemical Element |
| 78,466 | Scientific Names |
| 78,177 | Noble Gases |
| 76,759 | Name the Virus |
| 75,332 | Most Forested European Countries |
| 72,265 | Periodic Table Symbols |
| 71,843 | Science Vocabulary #1 |
| 70,707 | Periodic Table Elements Mentioned in the Bible |
| 70,052 | Name a Valid Element |
| 69,959 | Elements by Picture |
| 66,532 | Worst Plastic Polluting Countries |
| 65,206 | Least-Forested Countries |
| 64,975 | Dumb it Down Doc |
| 64,715 | Least Forested Countries in Asia |
| 64,657 | Countries Reducing Carbon Dioxide Emissions the Most |
| 64,591 | Elements that are Gases at Room Temperature |
| 63,442 | Top 10 Most Forested Countries in Asia |
| 63,279 | Body Parts - Sudden Death #1 |
| 62,777 | Electromagnetic Spectrum |
| 62,518 | Periodic Table Elements by Clue #1 |
| 59,988 | Top 10 Solar Power Countries |
| 59,821 | Animal Anatomy Quiz |
| 59,654 | Science Vocabulary #2 |
| 59,106 | Medical Vocabulary |
| 57,781 | Diseases and Medical Conditions A-Z |
| 56,884 | First Names of Scientists |
| 56,843 | Planets By Picture Quiz |
| 55,648 | Countries with Tropical Rainforest and Glaciers |
| 55,564 | One Letter Periodic Table Symbols - Sudden Death |
| 55,487 | Countries with the Most Forest A-Z |
| 55,026 | Answers are Elements #2 |
| 54,891 | Word Chain - Science |
| 54,019 | Least Forested European Countries |
| 53,984 | Things Named For People #3 - Science |
| 53,692 | Category Elimination - Elements |
| 53,574 | Planets - Multiple Choice |
| 52,829 | Answers are Elements #1 |
| 52,295 | Elemental Words |
| 51,998 | Science Vocabulary #3 |
| 50,723 | 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 |
| 46,660 | Solar System Trivia |
| 46,521 | Top 10 Least-Forested U.S. States |
| 46,495 | Animals by Skeleton Image |
| 45,637 | Top 10 Most-Forested U.S. States |
| 45,292 | Countries with the Most Malaria Deaths |
| 44,982 | Name the Constellations |
| 44,447 | Countries with the Most HIV |
| 43,498 | Fish... or Not a Fish? |
| 42,649 | Famous Scientists |
| 42,449 | Bones of the Human Body |
| 42,276 | First 30 Elements Periodic Table |
| 42,071 | Citrus Fruits |
| 41,666 | Countries that Desalinate the Most Water |
| 40,956 | Name a Valid Answer - Science |
| 40,307 | Science True or False |
| 38,704 | Diseases: Virus... or Bacteria? |
| 38,058 | Astronomy Decoder |
| 37,815 | Countries with the Highest Percentage of Forest |
| 36,580 | Science Multiple Choice #2 |
| 36,473 | Astronomy True or False |
| 36,424 | First Twenty Elements - Sudden Death |
| 36,147 | Northernmost Countries Without Glaciers |
| 35,937 | Name the Constellations - With a Map |
| 35,398 | Largest Countries Without Glaciers |
| 35,282 | Body Parts in History and Culture |
| 34,683 | The Sun Quiz |
| 34,629 | Countries with the Most Mangroves |
| 34,618 | Science Multiple Choice #3 |
| 33,910 | Bones in the Human Body |
| 32,009 | Lightest Chemical Elements A-Z |
| 31,658 | Most Common Body Part Words |
| 29,325 | Rocks and Minerals Picture Quiz |
| 28,772 | Science Decoder |
| 28,320 | Brightest Natural Objects in the Sky |
| 28,287 | Animals - Taxonomy to Common Name |
| 26,834 | Environmental Issues |
| 26,388 | U.S. States with the Most Drug Overdose Deaths |
| 25,821 | Top 10 U.S. States by Solar Power |
| 25,347 | Body Parts - No Vowels |
| 25,304 | U.S. States with Glaciers |
| 24,705 | Elements Named for Countries |
| 21,197 | First 40 Elements |
| 20,810 | 16 Questions that Prove that Physics Makes No Sense |
| 19,643 | Click Every Chemical Symbol |
| 18,667 | The Mars Quiz |
| 18,391 | Albert Einstein Trivia |
| 17,846 | Elements Whose First Letter Doesn't Match the Symbol |
| 17,257 | Countries with the Most Sunlight Per Square Meter |
| 16,460 | The Jupiter Quiz |
| 15,523 | First 50 Elements |
| 14,714 | Recommended Childhood Vaccines for Americans |
| 14,482 | The Voyage of Darwin - Animated Map Quiz |
| 14,009 | The Diseases They Had |
| 13,917 | Elements of the Periodic Table by Symbol |
| 13,751 | Name the Metal Alloy |
| 13,061 | Periodic Table Symbols - Sudden Death |
| 12,708 | Body Parts - Sudden Death #2 |
| 12,560 | Medicine and Anatomy by Letter - A |
| 12,510 | Famous Effects |
| 12,182 | Periodic Table Elements by Clue #2 |
| 11,556 | The Saturn Quiz |
| 11,554 | A Quiz About Diamonds |
| 11,356 | Random Elements on the Periodic Table |
| 10,948 | 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 |
| 8,208 | Periodic Table of Elements - in Order |
| 8,179 | Medication... or Pokémon? |
| 7,747 | The Elements of the Periodic Table |
| 7,637 | All Elements of The Periodic Table - Sudden Death (Hard) |
| 7,592 | Name Elements Containing Each Letter A-Z |
| 7,319 | Organs of the Body |
| 7,318 | Click the Chemical Element #2 |
| 6,925 | The Venus Quiz |
| 6,835 | Science General Knowledge #1 |
| 6,826 | Constellation Map |
| 6,781 | Countries That Discovered the Elements of the Periodic Table |
| 6,700 | First 28 Countries of Wuhan Coronavirus COVID-19 Outbreak |
| 6,280 | Moons of the Solar System |
| 6,245 | Random Constellations on a Map |
| 6,068 | 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 |
| 5,628 | Medicine and Anatomy by Letter - C |
| 5,519 | Elements of The Periodic Table - Sudden Death |
| 5,442 | 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 |
| 4,998 | 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 |
| 4,565 | 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 |
| 4,426 | Physics A-Z |
| 4,285 | Periodic Table Quiz by Borders in 60 Seconds |
| 4,166 | Muscles of the Human Body |
| 4,146 | Seven Strong Acids Quiz |
| 4,112 | Amino Acid Structures |
| 4,049 | Musical Movies - Sudden Death #2 |
| 4,044 | Medicine and Anatomy by Letter - E |
| 3,978 | Anatomy of the Human Eye Map Quiz |
| 3,970 | First 36 Periodic Table Elements |
| 3,953 | Name the 20 Amino Acids |
