Chemical Bonds
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50 free Chemical Bonds trivia questions with answers — science & nature quiz, new questions added Oct 2026.
Chemical bonds are the reason there is anything to look at. A handful of rules about how atoms share, give away or pool their electrons decides whether a substance is a gas you breathe, a crystal you sprinkle on dinner or the hardest gemstone on Earth. The same rules explain why ice floats, why a lizard can walk up a window and why a perm keeps its curl. This quiz covers the ground a high school or first-year college chemistry class does. There are questions on ionic and covalent bonding and how to tell them apart, on electron dot diagrams, on bond angles and the shapes of molecules, on the bonding inside metals, and on the weaker attractions that act between molecules. Others look at the chemists who worked out the rules and at the bonds at work in everyday materials and in living things. The opening questions are easy enough for anyone who remembers a little school science, and the later ones will stretch a student revising for a test. Every answer comes with a short explanation, so a wrong guess still teaches you something. Play online or print the questions for a classroom.
30 of 50 questions with answers and explanations. Play the quiz
Q 01Which lizard's grip on glass has long been credited to van der Waals forces from tiny hairs on its feet?
Gecko
Gecko footpads pack about 14,000 hair-like setae into every square millimeter. Forces this weak only add up to a firm grip over a very large contact area.
Q 02Which gemstone is pure carbon, each atom covalently bonded to its neighbors in a rigid 3D network?
Diamond
Diamond has more atoms per unit volume than any other known substance, which is why it is both the hardest and the least compressible.
Q 03Which attraction between water molecules makes ice less dense than liquid water, so that it floats?
Hydrogen bonding
Hydrogen bonding locks the molecules of ice into an open hexagonal framework, so the solid is about 8% less dense than the liquid. Floating ice keeps lakes from freezing from the bottom up.
Q 04Which kitchen staple dissolves in water as whole molecules, not ions, because it is covalently bonded?
Table sugar
Table sugar is a non-electrolyte: its molecules stay whole in water instead of breaking into ions. Salt water conducts electricity because its dissolved ions are free to move.
Q 05Which metal, used in light-bulb filaments, owes its record-high melting point to strong bonds between its atoms?
Tungsten
Tungsten melts at 3,422 °C, hotter than any other metal, and has the highest tensile strength of any pure metal. That toughness puts it in heating elements and rocket engine nozzles.
Q 06Which bonds between protein chains in hair does a perm break and then re-form to hold a new curl?
Disulfide
Disulfide bridges give hair its elasticity. With the hair wound on rods, a perm lotion breaks them open and an oxidizing lotion closes them again in the rod's shape.
Q 07Which molecule's ring structure did August Kekulé say came to him in a daydream of a snake seizing its own tail?
Benzene
Benzene is a ring of six carbon atoms, and Kekulé said the idea came from a reverie of a snake biting its tail. The image is an ancient symbol called the ouroboros.
Q 08Which American chemist won the 1954 Nobel Prize in Chemistry for research into the nature of the chemical bond?
Linus Pauling
Linus Pauling went on to win the 1962 Nobel Peace Prize as well, making him the only person to have been awarded two unshared Nobel Prizes.
Q 09Which metal is liquid at room temperature because its atoms bond to one another unusually weakly?
Mercury
Mercury is the only metal that is liquid at standard temperature and pressure. Relativistic effects pull its outermost electrons in tight, which weakens the bonding between its atoms.
Q 10Which group of elements almost never forms bonds because their outer electron shells are already full?
Noble gases
Noble gases were once called the inert gases, but that label was dropped after chemists managed to make compounds of several of them.
Q 11Which model, refined by Gillespie and Nyholm in 1957, predicts a molecule's shape from repulsion between electron pairs?
VSEPR theory
VSEPR theory treats the electron pairs around an atom as pushing each other as far apart as possible. The core idea was first proposed in 1939 by Ryutaro Tsuchida in Japan.
Q 12What shape is a methane molecule, whose four hydrogen atoms sit 109.5 degrees apart around a central carbon?
Tetrahedral
Tetrahedral geometry puts the four hydrogen atoms as far apart in space as they can get. Laid flat in a square, they would be only 90 degrees apart.
Q 13What is the approximate angle between the two O–H bonds in a water molecule, squeezed by two lone pairs on oxygen?
104.5°
Q 21Which bonding guideline, ignored by hydrogen and helium, explains why sodium hands one electron to chlorine?
Octet rule
The octet rule says main-group atoms tend to bond until each has eight electrons in its outer shell. Sodium gets there by losing its single outer electron, chlorine by gaining one.
Q 22What name, from the Greek for down, is given to a positively charged ion such as sodium that has lost an electron?
Cation
Cation is one of the words the polymath William Whewell coined for Michael Faraday, along with anion, anode and cathode. A cation is smaller than the atom it came from.
Q 23Which electrons, the only ones drawn in an electron dot diagram, occupy a main-group atom's outermost shell?
Valence
104.5° is a little less than the 109.5° found in methane, because the two unshared pairs sit closer to the oxygen and push the O–H bonds toward each other.
Q 14Which gas that humans breathe out has a straight, linear molecule with a bond angle of 180 degrees?
Carbon dioxide
Carbon dioxide is perfectly symmetrical, with the carbon in the middle, so the pull of one oxygen cancels the other and the molecule has no electric dipole.
Q 15What is the bond angle in boron trifluoride, a flat molecule with three fluorine atoms spaced evenly around boron?
120°
120° is the angle that spreads three bonds evenly around a flat circle, a shape chemists call trigonal planar. Boron here has only six outer electrons, so the molecule is called electron deficient.
Q 16Which pungent gas has a trigonal pyramidal molecule, with three hydrogen atoms at bond angles of about 107 degrees?
Ammonia
Ammonia has a lone pair of electrons on its nitrogen atom that takes up the fourth corner and pushes the three bonds together. That same pair makes the gas a base.
Q 17What shape is sulfur hexafluoride, in which six fluorine atoms surround one sulfur atom at 90-degree angles?
Octahedral
Octahedral means eight faces, not eight atoms: the six fluorines sit at the six corners of the solid. The gas is so dense that breathing it makes a voice sound deeper.
Q 18What shape is an ozone molecule, whose three oxygen atoms meet at an angle of about 117 degrees?
Bent
Bent is also the shape of a water molecule. A ring-shaped form of ozone has been predicted by theory but never made in bulk.
Q 19Which American chemist, who sketched atoms as cubes, gives his name to the dot diagrams of bonding electrons?
Gilbert N. Lewis
Gilbert N. Lewis published the diagrams in 1916 and was nominated for a Nobel Prize 41 times without ever winning. He also coined the word photon.
Q 20Which property, highest of all in fluorine, measures how strongly an atom pulls shared electrons toward itself?
Electronegativity
Electronegativity runs from about 0.8 for cesium to nearly 4 for fluorine on the usual scale. The wider the gap between two bonded atoms, the more lopsided their sharing becomes.
Valence electrons are the ones that can take part in bonding, which is why the diagrams show only them. Transition metals break the pattern: theirs can also sit in an inner shell.
Q 24How many dots surround the symbol Cl in an electron dot diagram of chlorine, a group 17 halogen?
Seven
Seven dots stand for the seven electrons in chlorine's outer shell, one short of a full set. That single gap makes chlorine quick to take an electron from many other elements.
Q 25Which fiber used in bulletproof vests owes its strength to countless weak bonds linking its stiff chains side by side?
Kevlar
Kevlar is five times stronger than steel for its weight. The chemist Stephanie Kwolek invented it at DuPont, and it was first sold as a steel replacement in racing tires.
Q 26What is the formula of magnesium chloride, in which each magnesium atom gives up two electrons to chlorine atoms?
MgCl2
MgCl2 needs two chloride ions because each chlorine atom can take only one electron, while magnesium has two to give. The salt is extracted from seawater and brine.
Q 27Which pair of elements bonds ionically to form a salt once widely used as a sedative?
Potassium and bromine
Potassium and bromine form potassium bromide, widely used as a sedative and epilepsy drug in the late 1800s. As a typical ionic salt, it splits fully into ions in water.
Q 28What holds the oppositely charged sodium and chloride ions together in an ionic bond?
Electrostatic attraction
Electrostatic attraction pulls on every nearby opposite charge, not just one partner. In solid sodium chloride each ion is surrounded by six ions of the opposite charge.
Q 29What name is given to the regular, repeating three-dimensional arrangement of ions in a crystal of table salt?
Lattice
A lattice like this has no separate molecules in it, so chemists do not class ionic compounds as molecular at all.
Q 30In which state does solid table salt, normally an electrical insulator, become able to conduct electricity?
Molten
Molten salt conducts because its ions, fixed in place in the solid, become free to move and carry charge. Dissolving the salt in water frees them in the same way.