Science Quiz — Hard 30 — Free Science Quiz

1. What is the approximate age of the universe?

💡 The universe is approximately 13.8 billion years old as determined by measurements of the cosmic microwave background.

2. What law states the pressure of a gas is inversely proportional to its volume at constant temperature?

💡 Boyle's Law states that at constant temperature pressure times volume remains constant. Formulated by Robert Boyle in 1662.

3. What is the Chandrasekhar Limit?

💡 The Chandrasekhar Limit (1.4 solar masses) is the maximum mass a white dwarf can have before collapsing.

4. Which element has the highest electronegativity on the periodic table?

💡 Fluorine has the highest electronegativity at 3.98 on the Pauling scale and reacts with almost any substance.

5. What is the photoelectric effect?

💡 Einstein won the 1921 Nobel Prize for explaining the photoelectric effect — proving light behaves as particles called photons.

6. What is the SI unit of electric charge?

💡 The coulomb is the SI unit of electric charge. One coulomb is transported by a current of one ampere in one second.

7. What is the boundary between Earth's crust and mantle called?

💡 The Mohorovicic Discontinuity (Moho) lies about 35 km below continents and 7 km below oceans.

8. What is the theoretical boundary around a black hole beyond which nothing can escape?

💡 The event horizon is the point of no return around a black hole. Once anything crosses this boundary it cannot escape.

9. Which subatomic particles make up protons and neutrons?

💡 Protons and neutrons are made of quarks — fundamental particles that come in 6 types.

10. What is the chemical formula for glucose?

💡 Glucose is C6H12O6 — 6 carbon 12 hydrogen and 6 oxygen atoms. It is the primary source of energy for living cells.

Science Quiz — Hard 30