Science Quiz Questions & Answers

Why Science Knowledge Matters

Science literacy is essential in the modern world. Understanding basic scientific principles helps you make informed decisions about health, technology, and the environment. Science quiz questions test your grasp of how the natural world works.

Physics — Key Facts for Quiz Success

• ⚡ Speed of light: 299,792,458 metres per second
• 🍎 Newton's First Law: Objects remain at rest or in uniform motion unless acted upon by a force.
• 🔋 E = mc² means energy equals mass times the speed of light squared.
• 🧲 Opposite magnetic poles attract; like poles repel.
• 🌡️ Absolute zero is −273.15°C (0 Kelvin) — the coldest possible temperature.
• 🔊 Sound travels at approximately 343 m/s in air at room temperature.

Chemistry — Essential Quiz Knowledge

• 💧 Water's chemical formula is H₂O — two hydrogen atoms bonded to one oxygen.
• 🧪 The most abundant element in the universe is Hydrogen.
• ⚗️ The most abundant element in Earth's crust is Oxygen (46%).
• 🔥 Combustion requires three elements: fuel, oxygen, and heat (the "fire triangle").
• 💎 Diamond is the hardest natural substance (10 on Mohs scale); graphite is the softest form of carbon.
• 🧂 Common table salt is Sodium Chloride (NaCl).

Biology — Must-Know Facts

• 🦠 The human body contains approximately 37.2 trillion cells.
• 🧬 DNA stands for Deoxyribonucleic Acid — the molecule that carries genetic information.
• ❤️ The human heart beats approximately 100,000 times per day.
• 🫁 The largest organ is the skin — the liver is the largest internal organ.
• 🐛 Insects are the most numerous animals on Earth, comprising over 80% of all animal species.
• 🌿 Photosynthesis produces oxygen and glucose using sunlight, water, and CO₂.

Astronomy — Space Science Quiz Questions

• 🌍 Earth is the third planet from the Sun, approximately 150 million km away.
• ☀️ The Sun is a G-type main-sequence star — one of 200–400 billion stars in the Milky Way.
• 🪐 Saturn's rings are made of ice and rock particles, some as small as grains of sand.
• 🌑 A light-year is the distance light travels in one year: approximately 9.46 trillion km.
• 🔭 The Hubble Space Telescope was launched in 1990.
• 🚀 The first human in space was Yuri Gagarin in April 1961.

100 Science Quiz Questions Answered

Physics (25 Questions)

1. What force keeps planets in orbit around the Sun? (Gravity)
2. What type of energy does a moving object have? (Kinetic energy)
3. What is the unit of electrical resistance? (Ohm)
4. What phenomenon explains why the sky is blue? (Rayleigh scattering)
5. What is the boiling point of water in Fahrenheit? (212°F)
6. What is the unit of force in the SI system? (Newton)
7. What is the speed of sound in air called when exceeded? (Supersonic / breaking the sound barrier)
8. What law states that every action has an equal and opposite reaction? (Newton's Third Law)
9. What is the unit of electrical current? (Ampere)
10. What type of lens is used to correct short-sightedness? (Concave lens)
11. What is the SI unit of frequency? (Hertz)
12. What force opposes motion between two surfaces in contact? (Friction)
13. What is the unit of power? (Watt)
14. What principle explains why ships float? (Archimedes' Principle / buoyancy)
15. What is the term for the bending of light as it passes between media? (Refraction)
16. What is the SI unit of pressure? (Pascal)
17. What type of mirror is used in car headlights? (Concave mirror)
18. What is the value of acceleration due to gravity on Earth? (9.8 m/s²)
19. What is the unit of energy? (Joule)
20. What law states that pressure and volume of a gas are inversely proportional? (Boyle's Law)
21. What is the term for the resistance of an object to changes in motion? (Inertia)
22. What instrument measures atmospheric pressure? (Barometer)
23. What is the unit of electric charge? (Coulomb)
24. What phenomenon causes a rainbow? (Dispersion of light)
25. What is the term for the study of motion without considering forces? (Kinematics)

Chemistry (25 Questions)

1. What is the atomic number of carbon? (6)
2. Which gas is used in party balloons? (Helium)
3. What is the pH of pure water? (7 — neutral)
4. What metal is liquid at room temperature? (Mercury)
5. What is dry ice made of? (Solid carbon dioxide)
6. What is the chemical symbol for gold? (Au)
7. What is the most abundant gas in Earth's atmosphere? (Nitrogen, ~78%)
8. What type of bond involves the sharing of electron pairs? (Covalent bond)
9. What is the chemical formula for table sugar? (C₆H₁₂O₆ — glucose)
10. What gas do plants absorb during photosynthesis? (Carbon dioxide)
11. What is the chemical symbol for iron? (Fe)
12. What is an acid that turns blue litmus paper red? (Any acid, e.g. hydrochloric acid)
13. What is the lightest chemical element? (Hydrogen)
14. What process turns a liquid directly into a gas? (Evaporation / vaporization)
15. What is the chemical name for rust? (Iron oxide)
16. What is the most reactive group of metals on the periodic table? (Alkali metals)
17. What is the chemical symbol for sodium? (Na)
18. What term describes a substance that speeds up a reaction without being consumed? (Catalyst)
19. What is the chemical formula for methane? (CH₄)
20. What gas makes up most of the air we exhale? (Carbon dioxide and nitrogen)
21. What is the term for a substance made of two or more elements chemically combined? (Compound)
22. What is the freezing point of water in Celsius? (0°C)
23. What is the chemical symbol for potassium? (K)
24. What type of reaction releases heat? (Exothermic reaction)
25. What is the smallest unit of an element that retains its properties? (Atom)

Biology (25 Questions)

1. How many chambers does the human heart have? (4)
2. What organ produces insulin? (Pancreas)
3. What is the basic unit of life? (Cell)
4. How many bones are in the adult human body? (206)
5. What type of blood cells carry oxygen? (Red blood cells / Erythrocytes)
6. What is the powerhouse of the cell? (Mitochondria)
7. What gas do humans breathe out as a waste product? (Carbon dioxide)
8. What is the largest organ in the human body? (Skin)
9. What part of the cell contains genetic material? (Nucleus)
10. What is the process by which plants make food using sunlight? (Photosynthesis)
11. What organ filters waste from the blood? (Kidneys)
12. What is the green pigment in plants called? (Chlorophyll)
13. How many pairs of chromosomes do humans have? (23 pairs)
14. What is the medical term for low blood sugar? (Hypoglycemia)
15. What type of cell division produces identical daughter cells? (Mitosis)
16. What is the term for an organism's complete set of DNA? (Genome)
17. What organ is responsible for pumping blood? (Heart)
18. What is the study of heredity called? (Genetics)
19. What white blood cells help fight infection? (Leukocytes)
20. What is the longest bone in the human body? (Femur / thigh bone)
21. What enzyme in saliva begins starch digestion? (Amylase)
22. What is the term for animals that eat only plants? (Herbivores)
23. What part of the brain controls balance? (Cerebellum)
24. What is the process by which water moves through a cell membrane called? (Osmosis)
25. What pigment gives blood its red color? (Hemoglobin)

Astronomy & Earth Science (25 Questions)

1. Which planet is closest to the Sun? (Mercury)
2. What is the name of our galaxy? (The Milky Way)
3. What is the largest planet in our solar system? (Jupiter)
4. How long does it take Earth to orbit the Sun? (365.25 days)
5. What causes the phases of the Moon? (The Moon's changing position relative to Earth and Sun)
6. What is a shooting star actually called? (A meteor)
7. What planet is known for its prominent ring system? (Saturn)
8. What is the term for a star's explosive death? (Supernova)
9. What is the closest star to Earth (besides the Sun)? (Proxima Centauri)
10. What causes tides on Earth? (The gravitational pull of the Moon, and to a lesser extent the Sun)
11. What is the layer of Earth we live on called? (The crust)
12. What is the study of earthquakes called? (Seismology)
13. What type of rock forms from cooled magma or lava? (Igneous rock)
14. What is the Earth's only natural satellite? (The Moon)
15. What instrument is used to detect earthquakes? (Seismograph)
16. What is the outermost layer of Earth's atmosphere called? (Exosphere)
17. What planet is known as the Red Planet? (Mars)
18. What causes a solar eclipse? (The Moon passing between the Sun and Earth)
19. What is the boundary where tectonic plates meet called? (Fault line)
20. What is the term for the path a planet takes around the Sun? (Orbit)
21. What gas layer protects Earth from UV radiation? (The ozone layer)
22. What is the largest moon in our solar system? (Ganymede, orbiting Jupiter)
23. What type of cloud is associated with thunderstorms? (Cumulonimbus)
24. What is the process by which rock is broken down over time? (Weathering)
25. What is the term for a region with consistent weather patterns over time? (Climate)

Tips to Ace Science Quizzes

1. Learn the periodic table basics — at least the first 20 elements.
2. Understand key formulas — F=ma, E=mc², PV=nRT.
3. Watch science YouTube channels — Kurzgesagt, MinutePhysics, Veritasium.
4. Practice with timed quizzes — speed matters in competitive settings.
5. Connect concepts — understanding WHY is more memorable than memorizing facts.