Science for grades 11–12: questions with answers
The Science questions for grades 11–12 from the game, with the correct answers and an explanation for each.
What is absolute zero in degrees Celsius?
- -459 °C
- -273 °C
- -100 °C
- 0 °C
Correct answer: -273 °C — At -273.15 °C, or 0 kelvin, particles have the least possible energy. It cannot be reached, but laboratories have come within billionths of a degree.
Avogadro's number is about 6.02 multiplied by 10 to which power?
- 10
- 23
- 32
- 46
Correct answer: 23 — One mole of any substance contains 6.02 × 10²³ particles. A mole of water weighs just 18 grams but holds that enormous number of molecules.
Which organelle assembles proteins in the cell?
- Ribosome
- Lysosome
- Golgi apparatus
- Vacuole
Correct answer: Ribosome — Ribosomes read the genetic code and string amino acids together into proteins. A single cell may contain millions of them.
Which base is found in RNA but not in DNA?
- Thymine
- Uracil
- Adenine
- Guanine
Correct answer: Uracil — DNA uses adenine, thymine, guanine and cytosine. RNA replaces thymine with uracil.
What is the boundary of a black hole beyond which nothing can escape called?
- Singularity
- Accretion disc
- Event horizon
- Photon sphere
Correct answer: Event horizon — Inside the event horizon the escape velocity exceeds the speed of light. The first image of a black hole's shadow was published in 2019.
Who formulated the three laws of planetary motion describing elliptical orbits?
- Kepler
- Brahe
- Galileo
- Halley
Correct answer: Kepler — Johannes Kepler showed in 1609 that planets move in ellipses, not circles, using Tycho Brahe's precise observations of Mars.
How many faces does a regular icosahedron have?
- 8
- 12
- 20
- 30
Correct answer: 20 — The icosahedron has 20 triangular faces — the most of the five Platonic solids. Many viruses have this shape.
Which theorem on aⁿ + bⁿ = cⁿ was finally proved by Andrew Wiles in the 1990s?
- Pythagoras' theorem
- Fermat's Last Theorem
- Goldbach's conjecture
- Bayes' theorem
Correct answer: Fermat's Last Theorem — Fermat wrote in 1637 that he had a proof but the margin was too small to hold it. It took 358 years and over 100 pages of modern mathematics.
What is the SI unit of magnetic flux density?
- Tesla
- Weber
- Gauss
- Henry
Correct answer: Tesla — The tesla honours Nikola Tesla, pioneer of alternating current. A fridge magnet is about 0.005 tesla; a hospital MRI scanner is 1.5 to 3 tesla.
For which discovery did Einstein receive the 1921 Nobel Prize in Physics?
- Photoelectric effect
- Special relativity
- Brownian motion
- Mass–energy equivalence
Correct answer: Photoelectric effect — Einstein's Nobel citation named the photoelectric effect, not relativity. His explanation that light comes in packets of energy helped found quantum theory.
Which metal has the highest melting point?
- Iron
- Platinum
- Titanium
- Tungsten
Correct answer: Tungsten — Tungsten melts at about 3,400 °C, which is why it was used for the filaments of light bulbs. Its symbol W comes from its German name, Wolfram.
Which is the most electronegative element?
- Oxygen
- Chlorine
- Fluorine
- Nitrogen
Correct answer: Fluorine — Fluorine pulls electrons more strongly than any other element and reacts with almost everything, even some noble gases.
Which enzyme in saliva begins the digestion of starch?
- Pepsin
- Lipase
- Amylase
- Trypsin
Correct answer: Amylase — Amylase breaks starch into sugars, which is why bread starts to taste sweet if chewed for long enough. Pepsin works in the stomach on proteins.
Whose experiments with pea plants laid the foundations of genetics?
- Darwin
- Lamarck
- Pasteur
- Mendel
Correct answer: Mendel — Gregor Mendel, a monk in Brno, grew nearly 30,000 pea plants in the 1850s and 1860s. His work was ignored for 35 years and rediscovered in 1900.
What is the point in a planet's orbit closest to the Sun called?
- Aphelion
- Perigee
- Apogee
- Perihelion
Correct answer: Perihelion — Earth reaches perihelion in early January, about 147 million km from the Sun, and aphelion in early July. Seasons are caused by the axial tilt, not this distance.
What is the visible surface of the Sun called?
- Corona
- Chromosphere
- Photosphere
- Core
Correct answer: Photosphere — The photosphere is about 5,500 °C. Strangely, the corona above it is over a million degrees, and why it is so hot is still debated.
Which Greek mathematician wrote the Elements, the foundation of geometry?
- Archimedes
- Thales
- Pythagoras
- Euclid
Correct answer: Euclid — Euclid's Elements, written around 300 BC, was used as a geometry textbook for more than 2,000 years — longer than any other book.
What is the value of 0! (zero factorial)?
- 0
- 1
- Undefined
- Infinity
Correct answer: 1 — Zero factorial is defined as 1 — there is exactly one way to arrange nothing. This keeps formulas for combinations working.
Who discovered the electron in 1897?
- Rutherford
- Bohr
- Chadwick
- Thomson
Correct answer: Thomson — J. J. Thomson found the electron using cathode rays. Rutherford later discovered the nucleus, and Chadwick the neutron in 1932.
Chlorine and fluorine belong to which group of elements?
- Halogens
- Noble gases
- Alkali metals
- Alkaline earth metals
Correct answer: Halogens — The halogens — fluorine, chlorine, bromine, iodine and astatine — are so reactive that they are never found pure in nature. The name means 'salt-formers'.