11th Grade Science
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50 free 11th Grade Science trivia questions with answers — science & nature quiz, new questions added Oct 2026.
Eleventh grade is where high school science gets serious. For most American students it is the year of chemistry, with atoms, bonds and reactions to balance, while others take physics or a second year of biology. Whichever course is on the timetable, juniors are expected to connect ideas across all of them, which is what state exams and the science section of the ACT ask for. This quiz mixes the main ideas from each branch: how atoms are built and why elements behave as they do, forces, motion, waves and electricity, cells, genes and evolution, and the workings of our planet and the universe beyond it. You will also meet the scientists whose experiments rewrote the textbooks. Every answer comes with a short explanation, so a wrong guess still teaches something. Use it as a classroom review game, a warm-up before a test, or a challenge for any adult who wants to know how much of junior year stuck.
30 of 50 questions with answers and explanations. Play the quiz
Q 01Which gemstone, the hardest natural material, is made of the same element as pencil graphite?
Diamond
Diamond is pure carbon, exactly like graphite, but its atoms lock into a rigid crystal. At room pressure graphite is the stable form, so a diamond is very slowly turning into it.
Q 02Which kitchen staple, formula NaCl, joins a soft reactive metal to a poisonous yellow-green gas?
Table salt
Table salt is sodium chloride. Neither ingredient is safe alone: sodium is a soft, highly reactive metal, and chlorine was used as a poison gas in World War I.
Q 03Which precious metal has the chemical symbol Au, taken from the Latin name aurum?
Gold
Gold is the most malleable metal of all. A single gram can be beaten into a sheet covering one square metre, thin enough to become semi-transparent.
Q 04Which organelle, inherited almost only from the mother, makes the ATP that powers a cell?
Mitochondrion
The mitochondrion keeps its own small genome, similar to a bacterium's. That is a clue to its origin: its ancestor was a free-living microbe that fused with another cell long ago.
Q 05Which phenomenon makes an ambulance siren sound higher as it approaches and lower as it drives away?
Doppler effect
The Doppler effect is named after Christian Doppler, who described it in 1842. Astronomers use the same shift in starlight to measure how fast stars and galaxies approach or recede.
Q 06Which physicist's 1905 equation E = mc² showed that mass and energy are two forms of the same thing?
Albert Einstein
Albert Einstein published it in 1905, his 'miracle year' of four landmark papers. Because the speed of light squared is so large, a small amount of mass holds an enormous amount of energy.
Q 07Which naturalist's voyage aboard HMS Beagle led to the theory of evolution by natural selection?
Charles Darwin
Charles Darwin sailed from 1831 to 1836 and came home puzzled by the wildlife and fossils he had collected. On the trip he also ate puma, iguana, armadillo and giant tortoise.
Q 08Which element, the lightest of them all, makes up about 75% of the universe's normal matter?
Hydrogen
Hydrogen comes first on the periodic table, with atomic number 1. Counted by number of atoms rather than by mass, it makes up more than 90% of the universe's normal matter.
Q 09Which scientist, who named polonium after her native Poland, won Nobel Prizes in two sciences?
Marie Curie
Marie Curie remains the only person to win Nobel Prizes in two different sciences. She was also the first woman to win one at all, sharing the 1903 physics prize.
Q 10Which Italian scientist is said to have dropped unequal weights from the Leaning Tower of Pisa?
Galileo Galilei
Galileo Galilei's pupil Viviani told the story decades later, and most historians think it was a thought experiment. Its point: how long an object takes to fall does not depend on its mass.
Q 11Which SI unit, about 6.022 × 10²³ particles, do chemists use to count atoms and molecules?
Mole
A mole of anything is exactly 6.02214076 × 10²³ of it, a figure called the Avogadro number. Some chemistry classes celebrate Mole Day on October 23, written 10/23 in the US.
Q 12Which Russian chemist's periodic table predicted elements not yet discovered, such as gallium?
Dmitri Mendeleev
Dmitri Mendeleev claimed he saw the complete arrangement of the elements in a dream. He used his table to predict the properties of three elements nobody had found yet, scandium among them.
Q 13Which family of elements, including neon and argon, fills group 18 and almost never reacts?
Noble gases
Q 21By Newton's second law, force is mass times which quantity, measured in metres per second squared?
Acceleration
Acceleration is the rate at which velocity changes. The same law can be put another way: the net force on a body equals the rate at which its momentum is changing.
Q 22Which SI unit of energy is named after an English physicist who also managed his family's brewery?
Joule
The joule honours James Prescott Joule, a wealthy brewer's son. One joule is about the energy needed to lift an apple one metre.
Q 23What name is given to −273.15 °C, the lowest temperature theoretically possible?
Absolute zero
Absolute zero can be approached but never reached. Scientists in Bremen have cooled matter to 38 trillionths of a degree above it.
The noble gases have a full outer shell of electrons, which leaves them little tendency to react. Neon's name comes from the Greek for 'new', and xenon's from the word for 'stranger'.
Q 14Which type of chemical bond forms when two atoms share pairs of electrons, as in a methane molecule?
Covalent
Covalent bonding lets each atom reach the equivalent of a full outer shell by sharing electrons with a neighbour. Irving Langmuir introduced the word 'covalence' in 1919.
Q 15Which scale, devised by a Danish chemist at the Carlsberg Laboratory, measures acidity?
pH
The pH scale is logarithmic, and pure water sits at a neutral 7 at 25 °C. Søren Sørensen never explained what his letter p stood for, and its exact meaning is still disputed.
Q 16Which kind of substance, such as an enzyme, speeds up a reaction without being consumed?
Catalyst
A catalyst comes out of the reaction unchanged, so it can be recovered and reused. An estimated 90% of commercially produced chemical products rely on one at some stage of manufacture.
Q 17Which term describes a reaction, such as burning fuel, that releases heat into its surroundings?
Exothermic
Exothermic comes from the Greek for 'outward' and 'thermal'. Condensation counts too: steam gives out heat as it turns back into liquid water.
Q 18What are atoms of one element, such as uranium-235 and uranium-238, that differ in mass called?
Isotopes
Isotopes share one spot on the periodic table, and the name is Greek for 'the same place'. It was coined in 1913 by Margaret Todd, a Scottish doctor and writer.
Q 19Which particle's count in the nucleus sets the atomic number and decides which element an atom is?
Proton
The proton count is the atomic number, which uniquely identifies an ordinary element. Chemists of the 1800s ordered the elements by atomic weight instead, the only thing they could measure.
Q 20Which New Zealand-born physicist's team found the atomic nucleus by firing particles at metal foil?
Ernest Rutherford
Ernest Rutherford likened the particles that bounced back to a 15-inch shell rebounding off tissue paper. New Zealand put his portrait on its hundred-dollar note in 1992.
Q 24Which unit of electrical resistance is named after the German schoolteacher behind the law V = IR?
Ohm
The ohm honours Georg Ohm, who found that the current through a conductor is directly proportional to the voltage across it. Its symbol is the Greek capital letter omega.
Q 25Which form of energy, given by the formula ½mv², does any object have because of its motion?
Kinetic
Kinetic energy takes its name from the Greek word kinesis. Because speed is squared in the formula, a car going twice as fast carries four times as much of it.
Q 26Which property of a wave, measured in hertz, counts how many cycles pass a point each second?
Frequency
Frequency is what mostly decides the pitch of a sound. Human ears typically pick up between about 20 Hz and 20,000 Hz, and the upper limit usually drops with age.
Q 27Which property, described by Newton's first law, keeps a moving object moving unless a force acts?
Inertia
Inertia also keeps an object at rest sitting still until a force moves it. The word was taken from the Latin for 'idleness' or 'laziness'.
Q 28Which electromagnetic waves, first detected coming from radium, have the shortest wavelengths?
Gamma rays
Gamma rays were discovered in 1900 by the French scientist Paul Villard. Earth's atmosphere screens out a large fraction of those that arrive from space.
Q 29Which bending of light, as it passes from air into water or glass, lets a lens focus an image?
Refraction
Refraction happens when a wave changes speed as it crosses into a new medium. It is also responsible for rainbows, where raindrops split white light into colours.
Q 30Which measure of disorder, by the second law of thermodynamics, never falls in an isolated system?
Entropy
Entropy was named by Rudolf Clausius, who built the term from a Greek word for transformation. The same law is why heat flows on its own from hotter things to colder ones.