Science Crossword Puzzles Printable by Topic

Pick a set, then press Print for a science criss-cross crossword sorted by topic, from Tadpole to Hypothesis.

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Science Crossword

Read each clue and write the answer in the squares that start at its number, one letter in each square.

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Answer key: Science Crossword

1P2C3FREEZET4LUNGSAL5GILL6S7DKA8PREDICT9RLA10OXYGEN11RCTUK12GOGGLESENETR

Across 3 FREEZE · 4 LUNGS · 5 GILLS · 8 PREDICT · 10 OXYGEN · 12 GOGGLES

Down 1 PETAL · 2 CELL · 6 SKELETON · 7 DATA · 9 ROCKET · 11 RULER

Next step Find science words in a word searchScramble the unit's key words as a warm-up

All 160 clues

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Life Science 37

  • Amphibian Frog, toad or salamander: most kinds start life in water
  • Arachnid Spider, scorpion or tick: an animal with eight legs
  • Brain Organ inside the skull that controls the body
  • Camouflage Coloring that helps an animal blend in with its surroundings
  • Carnivore An animal that eats mostly meat
  • Cell The basic unit of every living thing
  • Chlorophyll Green pigment that lets a leaf absorb light
  • Decomposer Living thing, such as a mushroom, that breaks down dead plants and animals
  • Ecosystem The living things of a place together with its air, water and soil
  • Extinct No longer living anywhere, like the dodo
  • Fungus Mushroom, mold or yeast: neither a plant nor an animal
  • Gills A fish breathes with these
  • Habitat The natural home of a plant or an animal
  • Heart Organ that pumps blood around the body
  • Herbivore An animal that eats only plants
  • Hibernate To pass the winter in a deep sleep, as a groundhog does
  • Insect Animal with six legs and a body in three parts
  • Larva The young form of a moth or a beetle, such as a caterpillar or a grub
  • Lungs Pair of organs you breathe with
  • Mammal Animal with hair or fur that feeds its young on milk
  • Migration Seasonal journey made by many birds, whales and butterflies
  • Nocturnal Active at night, like an owl or a bat
  • Omnivore An animal that eats both plants and meat
  • Oxygen The part of the air that animals must breathe; green plants give it off
  • Petal One of the colored parts of a flower
  • Pollen Fine powder that bees carry from flower to flower
  • Predator An animal that hunts other animals for food
  • Prey An animal that is hunted and eaten by another
  • Pupa Resting stage between caterpillar and adult; a butterfly's is called a chrysalis
  • Reptile Scaly animal such as a snake, a lizard or a turtle
  • Root Plant part that takes in water from the soil
  • Seed A new plant can sprout from this
  • Skeleton The frame of bones inside your body
  • Skin The largest organ of the human body
  • Stem Plant part that holds up the leaves
  • Tadpole A young frog, still with a tail
  • Vertebrate An animal with a backbone

Earth Science and Weather 34

  • Atmosphere The blanket of air around our planet
  • Barometer Instrument that measures air pressure
  • Cirrus Thin, wispy cloud made of ice crystals, high in the sky
  • Condense What water vapor does on a cold window: it turns to drops
  • Core The hot center of our planet
  • Crust Thin, rocky outer layer of our planet
  • Cumulus Puffy white cloud with a flat base
  • Diamond Number 10 on the Mohs hardness scale
  • Earthquake Sudden shaking of the ground when rock slips along a fault
  • Erosion Wearing away of land by wind, water or ice
  • Evaporate What a puddle does on a hot day: it turns to vapor
  • Fossil Remains or print of a living thing from long ago, kept in rock
  • Frost Ice crystals on the grass on a cold morning
  • Glacier Slow-moving river of ice
  • Humidity The amount of water vapor in the air
  • Hurricane Huge spinning storm that forms over warm ocean water
  • Igneous Kind of rock formed when melted rock cools and hardens
  • Lava Melted rock that has reached the surface
  • Lightning Giant electric spark between a cloud and the ground
  • Magma Melted rock below the ground
  • Mantle Layer of hot rock about 2,900 km thick, under the continents and the ocean floor
  • Mineral Quartz, mica or feldspar, for example
  • Nitrogen It makes up about 78 percent of the air
  • Ozone High in the sky, a layer of it blocks most ultraviolet rays
  • Pumice Rock from an eruption, so full of bubble holes that it can float
  • Stalactite Icicle-shaped rock that hangs from a cave ceiling
  • Stalagmite Cone of rock that rises from a cave floor
  • Stratus Low, gray cloud that spreads over the sky in a flat sheet
  • Talc Number 1, the softest, on the Mohs hardness scale
  • Thunder Boom heard after a flash in a storm
  • Tide Rise and fall of the sea, about twice a day on most coasts
  • Tornado Spinning column of air that reaches from a storm cloud to the ground
  • Volcano Mountain that can erupt with ash and melted rock
  • Weather What the air outside is doing today: sunny, rainy or windy

Space 32

  • Apollo Program that landed the first people on another world, in 1969
  • Asteroid Rocky body smaller than a planet; most travel in a wide belt
  • Astronaut Person trained to travel and work in space
  • Aurora Glowing curtains of light in the sky near the poles
  • Axis Imaginary line through the poles that a planet spins around
  • Comet Ball of ice and dust that grows a long, glowing tail
  • Crater Bowl-shaped hole made when a space rock hits
  • Earth The only planet known to have life
  • Eclipse The darkening when one body in space passes into the shadow of another
  • Equinox Day in March or September when day and night are about equal
  • Galaxy Huge system of stars, such as the Milky Way
  • Gravity The pull that brings a dropped ball to the ground and holds the planets in their paths
  • Jupiter Largest planet, with a storm called the Great Red Spot
  • Mars The red planet, fourth in line
  • Mercury Smallest planet, with the shortest year: 88 days
  • Meteor Streak of light from a space rock burning up in the air, also called a shooting star
  • Moon It circles our planet about once every 27 days
  • Nebula Giant cloud of dust in space where new stars are born
  • Neptune Farthest planet, named for the Roman god of the sea
  • Orbit The path one body in space takes around another
  • Pluto Called a dwarf planet since 2006
  • Polaris The North Star
  • Revolve To travel around another body; our planet takes a year to do it
  • Rocket Vehicle that burns fuel to launch a spacecraft
  • Rotate To spin in place; our planet does it once a day
  • Satellite Any object, natural or built, that circles a planet
  • Saturn Planet famous for its bright, wide rings
  • Solstice Longest or shortest day of the year
  • Sun The star at the center of the solar system
  • Telescope Tool that gathers light to make far-off things look closer
  • Uranus Planet that spins tipped over on its side
  • Venus Hottest planet, wrapped in thick clouds

Physical Science 38

  • Atom Tiny particle that everything around you is built from
  • Battery Stored power for a flashlight, with a plus end and a minus end
  • Boil What water does at 100 degrees Celsius at sea level
  • Carbon Diamonds and pencil lead are both made of it
  • Circuit Closed loop of wire that electricity flows around
  • Conductor Material, such as silver or aluminum, that lets electricity flow easily
  • Density How tightly packed a material is: why a rock sinks and a cork floats
  • Dissolve What sugar does in hot tea
  • Echo Sound that bounces back to you
  • Electron Particle with a negative charge
  • Element Any one of the 118 entries on the periodic table
  • Energy The ability to do work or cause change
  • Force A push or a pull
  • Freeze What water does at 0 degrees Celsius
  • Friction The rubbing that slows a sliding box and warms your hands
  • Gold Metal with the symbol Au
  • Inertia Tendency of a moving object to keep moving and of a still one to stay still
  • Insulator Material, such as rubber or glass, that blocks the flow of electricity
  • Iron Metal with the symbol Fe; it rusts in damp air
  • Lens Curved piece of glass that bends light, as in eyeglasses
  • Lever Simple machine: a seesaw or a crowbar
  • Liquid It flows: it has a set volume but no fixed shape
  • Magnet It pulls steel paper clips and has a north and a south pole
  • Melt What an ice cube does in your hand
  • Mixture Things stirred together that can be separated again, like sand and salt
  • Molecule Two or more atoms joined together
  • Neutron Particle with no charge
  • Nucleus Dense center where protons and neutrons are packed
  • Pitch How high or low a sound is
  • Prism Block of glass that splits white light into a band of colors
  • Proton Particle with a positive charge
  • Pulley Simple machine: a rope running over a grooved wheel
  • Reflect What a mirror does to light
  • Screw Simple machine: a slope wrapped around a post
  • Solid Ice is water in this state; it keeps its own shape
  • Solution Salt water is one: the salt has spread evenly and cannot be seen
  • Steam Water in the form of a hot gas
  • Wedge Simple machine shaped like an ax blade; it splits things apart

Lab Tools and Method 19

  • Beaker Glass cup with a pouring lip, used for mixing and heating in a lab
  • Classify To sort things into groups by their features
  • Conclusion What you decide the results show, at the end of a lab report
  • Control The part of a test that is left unchanged, for comparison
  • Data Facts and measurements collected in a test
  • Experiment A fair test set up to answer a question
  • Flask Lab bottle with a wide body and a narrow neck
  • Funnel Cone that guides a pour into a narrow bottle
  • Goggles Eye protection worn in the lab
  • Graph Chart with bars, lines or plotted points
  • Hypothesis An idea you can test, stated before you begin
  • Measure To find a length, a weight or a temperature
  • Microscope Tool that makes tiny things look big enough to see
  • Observe To watch closely and note what happens
  • Predict To say what you think will happen next
  • Ruler Marked straightedge for finding lengths and drawing straight lines
  • Theory A well-tested explanation, such as plate tectonics
  • Thermometer Instrument that measures temperature
  • Variable The one thing you change on purpose in a fair test

How this list was compiled: 160 clues written for this site. The facts behind them were checked against English Wikipedia (en.wikipedia.org) in September 2026. Pluto is clued as a dwarf planet, so Mercury is the smallest planet and Neptune the farthest. Counts of moons are left out because they change. Nine clues sit in two sets, for example Telescope in Space and in Lab Tools; this list files each clue under one heading. Licence: own work

How it works

These science crossword puzzles, printable on Letter or A4, are vocabulary crosswords sorted into five topics: life, earth, space, physical science and lab method. The page opens on 12 Easy Science Clues, such as Tadpole, Volcano and Magnet.

Read the full guide

Match the set to the unit

Life Science runs from Seed to Chlorophyll and Decomposer. Earth Science and Weather, Space, Physical Science, and Lab Tools and Method cover the rest of the year. Easy Science Clues cuts across all five with short, familiar answers such as Lava and Echo. Press New puzzle for each table so neighbors cannot copy.

Numbers a textbook would give

Clues keep to facts that stay put: a year on Mercury lasts 88 days, nitrogen makes up about 78 percent of the air, and the periodic table has 118 elements. Counts that keep changing, such as how many moons a planet has, were left out.

  • Lab Tools and Method suits the first week of school: Hypothesis, Variable, Control and Conclusion come back in every lab report.
  • Tick Word bank under the clues in More options when a unit starts, and untick it for the review before the test.

Questions and answers

What grade are the science clues written for?

Easy Science Clues suits grades 3 and 4, with answers such as Root, Moon and Melt. The topic sets add upper elementary and middle school words such as Stalactite and Insulator. These bands are our judgement, not a published standard.

Why is Pluto not clued as a planet?

In 2006 the International Astronomical Union redefined the word planet, and Pluto has been classed as a dwarf planet since. The Pluto clue says so, which makes Neptune the farthest planet and Mercury the smallest.

Are these science crossword puzzles free to print?

Yes, with no sign-up and no limit on copies. The answer key prints last, and the line that starts "Print gives" says how many pages will come out. A few clues, such as Telescope, belong to two topics and can turn up in either set.

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