100 Chemistry Quiz Questions & Answers 2026

Periodic Table Questions — 25 Questions

1. How many elements are in the periodic table? (118)
2. What does the atomic number represent? (Number of protons)
3. What is the chemical symbol for oxygen? (O)
4. What element has the symbol Fe? (Iron)
5. What is the most abundant element in the universe? (Hydrogen)
6. Which element is named after Marie Curie's home country? (Polonium — Po, after Poland)
7. What is the lightest metal? (Lithium)
8. What is the chemical symbol for mercury? (Hg — from Latin Hydrargyrum)
9. Which group of elements are the noble gases? (Group 18)
10. What element is essential for plant growth and is a component of chlorophyll? (Magnesium)
11. What is the chemical symbol for tungsten? (W — from German Wolfram)
12. How many elements are metals? (About 94 of 118 elements are metals)
13. What is the radioactive element used in nuclear power plants? (Uranium — U)
14. What is the element with the highest atomic number found naturally? (Uranium — atomic number 92)
15. What element is used in fluorescent light bulbs? (Mercury — though LEDs are replacing them)
16. What are halogens? (Group 17 elements — Fluorine, Chlorine, Bromine, Iodine, Astatine)
17. What is the chemical symbol for calcium? (Ca)
18. Which element glows in the dark? (Radium — but modern glow-in-the-dark uses phosphors)
19. What is the rarest naturally occurring element on Earth? (Astatine — less than 1 gram in Earth's crust)
20. What is the chemical symbol for nitrogen? (N)
21. Who created the periodic table? (Dmitri Mendeleev, 1869)
22. What is the element number 79? (Gold — Au)
23. Which element is liquid at room temperature (other than mercury)? (Bromine — Br)
24. What is the atomic number of carbon? (6)
25. What element is used in pencils? (Graphite — a form of Carbon)

Chemical Reactions & Compounds — 25 Questions

1. What is a chemical equation? (Representation of a chemical reaction using symbols and formulas)
2. What is a catalyst? (Substance that speeds up a reaction without being consumed)
3. What is combustion? (Rapid reaction with oxygen producing heat and light)
4. What is an acid? (Substance with pH below 7, donates protons in solution)
5. What is a base? (Substance with pH above 7, accepts protons in solution)
6. What is neutralization? (Reaction between an acid and a base to form salt and water)
7. What is the formula for sulfuric acid? (H₂SO₄)
8. What is photosynthesis chemically? (6CO₂ + 6H₂O + light → C₆H₁₂O₆ + 6O₂)
9. What is oxidation? (Loss of electrons — "OIL" in OIL RIG)
10. What is reduction? (Gain of electrons — "RIG" in OIL RIG)
11. What is a polymer? (Large molecule made of repeating smaller units called monomers)
12. What is the chemical name for baking soda? (Sodium bicarbonate — NaHCO₃)
13. What is the formula for hydrogen peroxide? (H₂O₂)
14. What is a precipitate? (Insoluble solid that forms from a solution during a reaction)
15. What is distillation? (Purification by heating and condensing vapors)
16. What is chromatography? (Technique for separating mixtures based on movement through a medium)
17. What happens in an endothermic reaction? (Heat is absorbed from the surroundings — feels cold)
18. What is the formula for ammonia? (NH₃)
19. What is electrolysis? (Using electrical current to drive a non-spontaneous chemical reaction)
20. What is a mole in chemistry? (6.022 × 10²³ particles — Avogadro's number)
21. What is the formula for ethanol? (C₂H₅OH)
22. What is a buffer solution? (Solution that resists changes in pH)
23. What is saponification? (Process of making soap — reaction of fat with strong base)
24. What is the universal indicator used for? (Measuring pH — changes color across the pH scale)
25. What is the Maillard reaction? (Chemical reaction between amino acids and sugars causing browning in cooked food)

Famous Chemists — 25 Questions

1. Who discovered radium and polonium? (Marie Curie — first woman to win a Nobel Prize)
2. Who invented dynamite? (Alfred Nobel, 1867)
3. Who discovered penicillin? (Alexander Fleming, 1928)
4. Who created the first periodic table? (Dmitri Mendeleev, 1869)
5. Who is known as the father of modern chemistry? (Antoine Lavoisier)
6. Who proposed the atomic theory in the early 19th century? (John Dalton)
7. Who discovered the electron? (J.J. Thomson, 1897)
8. Who proposed the nuclear model of the atom? (Ernest Rutherford, 1911)
9. Who developed the Bohr model of the atom? (Niels Bohr, 1913)
10. Who is Fritz Haber known for? (Haber-Bosch process — synthesizing ammonia for fertilizer)
11. Who discovered oxygen independently? (Carl Wilhelm Scheele and Joseph Priestley)
12. Who named oxygen and hydrogen? (Antoine Lavoisier)
13. Which scientist developed polymer chemistry? (Hermann Staudinger)
14. Who won two Nobel Prizes in different sciences? (Marie Curie — Physics 1903, Chemistry 1911)
15. Who discovered nylon? (Wallace Carothers at DuPont, 1935)
16. Who is credited with discovering the law of conservation of mass? (Antoine Lavoisier)
17. Who proposed the concept of pH and the pH scale? (Søren Peder Lauritz Sørensen)
18. Who is known for Avogadro's Law relating gas volume to moles? (Amedeo Avogadro)
19. Who discovered the structure of benzene? (Friedrich August Kekulé)
20. Who is credited with isolating and naming chlorine? (Humphry Davy named it; Carl Wilhelm Scheele first isolated it)
21. Who developed the concept of chemical equilibrium? (Henri Louis Le Chatelier, known for Le Chatelier's Principle)
22. Who discovered radioactivity? (Henri Becquerel, in 1896)
23. Who is credited with developing the modern atomic theory of matter? (John Dalton)
24. Who won the Nobel Prize for synthesizing Vitamin C? (Albert Szent-Györgyi and Walter Norman Haworth)

Organic Chemistry & Everyday Substances — 25 Questions

1. What is organic chemistry the study of? (Compounds containing carbon)
2. What is the chemical formula for methane, the simplest hydrocarbon? (CH₄)
3. What is the main component of natural gas? (Methane)
4. What type of carbon compound forms the basis of all known life? (Organic compounds)
5. What is glucose's chemical formula? (C₆H₁₂O₆)
6. What are the building blocks of proteins called? (Amino acids)
7. What is the chemical name for vinegar's active ingredient? (Acetic acid)
8. What is the chemical formula for table sugar (sucrose)? (C₁₂H₂₂O₁₁)
9. What type of molecule stores genetic information? (DNA — deoxyribonucleic acid)
10. What is the term for molecules made of long chains of repeating units? (Polymers)
11. What is the main organic compound in plastic bottles? (Polyethylene terephthalate, PET)
12. What is the chemical formula for propane, used in gas grills? (C₃H₈)
13. What natural polymer makes up cotton and plant cell walls? (Cellulose)
14. What is the chemical term for fats and oils? (Lipids)
15. What gas do organic compounds release when burned with insufficient oxygen? (Carbon monoxide)
16. What is the active ingredient in aspirin? (Acetylsalicylic acid)
17. What is the chemical formula for citric acid, found in citrus fruits? (C₆H₈O₇)
18. What process converts crude oil into useful products like gasoline? (Fractional distillation / refining)
19. What is the main gas responsible for the greenhouse effect from fossil fuels? (Carbon dioxide)
20. What organic molecule gives plants their green color? (Chlorophyll)
21. What is the chemical name for the active stimulant in coffee? (Caffeine)
22. What is the simplest alcohol, used in alcoholic beverages? (Ethanol)
23. What natural rubber's chemical source comes from? (The latex sap of rubber trees, primarily Hevea brasiliensis)
24. What is the chemical term for the process where fat is converted to soap? (Saponification)
25. What organic compound class includes substances like cholesterol and steroids? (Lipids, specifically steroids)
26. What is the chemical term for the smallest repeating unit in a polymer chain? (A monomer)