Chemistry Crossword Puzzles [Essential Chemistry-aligned]

These crossword puzzles are intended for first-course students. Topical terms constitute the core of the word list. They come from PASCO Scientific’s Essential Chemistry textbook. Additional terms (to fill in the grid space) lean toward science, but sometimes wander into simple mathematics, general knowledge, technology, pop culture, geography, initialisms and acronyms, Roman numerals, or randomness.

Although this kind of activity may seem too simple for high school science, I discovered that it is not. I wrote a post detailing my surprising findings: Crosswords that work in college-prep courses.

I created these puzzles for use in high school courses. Because I was using crossword creator software, I chose to build as robust a crossword as possible. The more crosses, the better. The fewer blank spaces on the grid, the better. The chemistry topic vocabulary served as the core of the word list. I added “fair-game” terms to fill the gaps. While competing crosswords might have 20-30 words with a few dozen crosses, each of these has over 100 words with over 150 word crosses.

essential CHEMISTRY Crossword Puzzles 

Physics Crossword Puzzles (Essential Physics-aligned)

These crossword puzzles are intended for first-course students. Topical terms constitute the core of each word list. They come from PASCO Scientific’s Essential Physics textbook. Additional terms (to fill in the grid space) lean toward science, but sometimes wander into mathematics, general knowledge, technology, pop culture, geography, initialisms and acronyms, Roman numerals, or randomness.

Crossword puzzles in a high school physics course? I thought it was ... ill-advised. Until I tried it. The results were so surprising, I wrote a whole post about about it: Crosswords that work in college-prep courses.

I created these puzzles for use in high school courses. Because I was using crossword creator software, I chose to build as robust a crossword as possible. The more crosses, the better. The fewer blank spaces on the grid, the better. The physics topic vocabulary served as the core of the word list. I added “fair-game” terms to fill the gaps. While competing crosswords might have 20-30 words with a few dozen crosses, each of these has over 100 words with over 150 word crosses.

essential PHYSICS Crosswords at TPT

Crosswords that work in college prep courses

Crossword puzzles are amusements appropriate for elementary school students. Middle school at tops. They sit at the base of Bloom's taxonomy, and have no place in a rigorous high school college prep course,

Or so I thought.

I don't even remember what my impetus was for creating a series of crossword puzzles for my college prep physic course, but create I did. Computer software meant I could load a list of words and the computer would craft a puzzle grid. Then I could add words to flesh out the puzzle and fill the page.

What I didn't expect was student enthusiasm for the puzzles. That enthusiasm acted as a catalyst, and I worked out an implementation scheme.

High School Physics Crossword Puzzles [OpenStax-aligned]

The first set of crossword puzzles I posted on TPT consisted of puzzles I created years ago for my Conceptual Physics course. Next I posted a set intended for use with AP Physics students. Then I proceeded with crosswords aligned with the OpenStax Chemistry, Biology, and Astronomy textbooks.

The Chemistry textbook had a decent set of key terms for each chapter. Key terms in Biology were ... abundant! In the Astronomy textbook, I needed to supplement key terms with "non-key" terms from the chapters.

This brings me to the OpenStax Physics: High School textbook. I aimed for about 50 topical terms (key and non-key terms from each chapter along with review terms from previous chapters as needed). Additional terms were added to fill the gaps in the puzzle. Additional terms could be physics or science-related. But they could also be from random tops all over the general knowledge board. State nicknames, chemical symbols, tech, Roman numerals, and so on.

As ever, the resulting puzzles each include over 100 words with over 150 crosses. "Busy crosswords".

I gave crosswords to students as they finished unit tests. It gave quick test-takers something to do while classmates finished their tests. I gave them puzzles for the upcoming unit of study. Each puzzle had enough non-chapter terms to keep students engaged before and while learning the upcoming unit.

High School Physics Crosswords MEGABUNDLE at TPT

All 23 puzzles, bundled and steeply discounted.

High School Physics Crosswords Series One: Motion and Forces at TPT

Puzzles 1-5 bundled and discounted.

Astronomy Crossword Puzzles [OpenStax-aligned]

Who needs astronomy crossword puzzles? I have no idea! But if you do, I have some you might like. When I make crossword puzzles, I include appropriate chapter key terms; everyone does. But where most creators stop there, I take things further. I fill those awkward empty spaces (large enough to grow farm crops). I bring in non-key terms from the chapter, terms from previous chapters, science, math, general knowledge, pop culture, and randomness. That's among The Lessons of Phyz Advantages.

The good people at OpenStax have published Astronomy 2e on their site. Chapters 2-30 have key terms. So I am making crossword puzzles for those chapters. This post will grow one puzzle at a time until all puzzles are finished. Some chapters have very few key terms; those chapters are combined into a single puzzle.

My favorite use case is to distribute the next chapter's crossword puzzle on unit test day. That is, give out the Chapter 2 puzzle on Chapter 1 test day, and so on. It's nice for keeping the room quiet while students finish the test at different times from one another. You might naturally worry that students wouldn't have a chance with a puzzle filled with as-yet uncovered vocabulary. And you'd be right, except that I filled my puzzle space gaps with words they already know from previous chapters or general knowledge. Often the acronyms and initialisms are, well, very straightforward. The clue for NIST is National Institute for Science and Technology. I gave students the duration of the next unit to complete the puzzle.

2. Observing the Sky: The Birth of Astronomy at TPT [Free]

Word Count: 107   Word Crosses (Puzzle Score): 166

Key terms: Accelerate, Apparent, Astrology, Celestial, Circumpolar, Cosmology, Ecliptic, Epicycle, Equator, Geocentric, Heliocentric, Horizon, Horoscope, Parallax, Planet, Poles, Precession, Retrograde, Year, Zenith, Zodiac

Selected additional terms: Aquarius, Arabic, Aries, Astronomy, Cancer, Capricornus, Constellation, Copernicus, Diameter, Flat, Galileo, Geyser, Hubble, Jupiter, Leo, Libra, Magnet, Mars, Mercury, Meteor, Milky, Mol, Moon, Nasa, NIST, Nobel, Ophiuchus, Optics, Owl, Pauli, Pisces, Planetarium, Polaris, Ptolemy, Renaissance, Sagittarius, Scorpius, Sputnik, Starlink, STP, Sun, Syene, Taurus, Uranus, Virgo, Voyager

All puzzles include an online option for tech-savvy users who can upload files to a server space. Here's a sample of an online version.

https://phyz.org/crosswords/02-Birth

3. Orbits and Gravity at TPT

Words: 105   Puzzle Score: 162

Biology Crossword Puzzles [OpenStax-aligned]

With Conceptual and AP Physics crosswords covered, I moved on to Chemistry. Physics vocabulary is fairly pedestrian. We do our intimidation in the form of mathematics. Chemistry vocabulary wanders deeper into the esoteric: stoichiometry right off the bat. Pnictogen? Chemistry's got some words. 

Now that Chemistry's covered, it was time to move on to Biology. Intro Biology has very little math, so it brings the words. So many words that live their best lives within the confines of the study of life sciences. Endoplasmic reticulum arrives early and it's got plenty of friends.

Like the Chemistry puzzles, the Biology puzzles are aligned with an OpenStax online textbook. I chose Concepts of Biology this time. While nature may abhor a vacuum, I abhor crossword puzzles with yawning gaps and empty spaces. This time, some gaps were filled with terms from "100 Words Middle School Students Should Know" from vocabulary.com. Others were filled with terms from science, mathematics, geography, pop culture, and randomness. Students will be amused and surprised to see some of the terms that show up in these puzzles.

1. Introduction to Biology at TPT [Free]

Word Count: 108 · Puzzle Score (word crosses): 170

Core terms: Applied, Atom, Based, Basic, Biology, Biosphere, Cell, Community, Control, Deductive, Descriptive, Ecosystem, Eukaryote, Evolution, Falsifiable, Homeostasis, Hypothesis, Inductive, Law, Life, Macromolecule, Method, Molecule, Natural, Organ, Organelle, Organism, Peer, Phylogenetic, Physical, Population, Prokaryote, Science, System, Theory, Tissue, Variable

Selected additional terms: Acronyms, Adversary, AI, Air, Amber, Animal, Cheetah, Civic, Contortion, Cpu, Density, Divide, Earth, Elephant, Emu, Exodus, Eye, Gem, Hasten, Jupiter, Jut, Leopard, Lion, Mercury, Meter, Muscle, Navel, Neon, Neptune, Onion, Orion, Paris, Physics, Pluto, Quotient, Recluse, Slope, Twitch, Typhoons, URL, USB, xy

I posted this one online so you can see how the online version plays. Here's the link:

https://phyz.org/crosswords/01-Intro2Bio

2. Chemistry of Life at TPT

Words: 107 · Puzzle Score: 172

The Lessons of Phyz Advantages - Crosswords

CROSSWORD PUZZLES EDITION · [video question sets edition here]

Crossword puzzles in an academic core or AP lab class? Yes!

Crossword puzzles are a simple exercise in matching clues to words. Except the word, itself, is not given. The number of letters is given. And as the grid is filled in, letters of the words become apparent. By the time students ere sitting in the high school science class, they know how to work crossword puzzles without any instruction.

Does the puzzle engage students in the highest reaches of Bloom's taxonomy? No. But that's okay. Lower level retrieval has a place in the curriculum, too. And sometimes, spelling could benefit from this kind of reenforcement. In any case, students are involved in academic vocabulary.

My AP students would tear into crossword puzzles with no promise of a reward. They couldn't resist the challenge. Among grade-level Physics students, the ones who seemed most engaged in the crossword puzzles tended to be the students who were otherwise least engaged in the course as a whole. Compared to challenging conceptual questions or mathematical problems, knocking out answers on the crossword seemed much more manageable. 

And then there were the words that were not on the chapter's vocabulary list. For my original Physics crossword series, I leaned into a list of "100 Words Every High School Graduate Should Know" I found on the Internet. My English-teaching colleagues always appreciated this. Some even offered a few terms that weren't on the Internet's list.

For subsequent series (AP Physics, Chemistry, etc.), I loosened up a bit. Taylor Swift references? K-pop? Star Wars? Why not? Each puzzle's description on TPT includes the complete word list. There you can see that I did work Metallica, Megadeth, and Judas Priest into the chemistry crossword about metals. Because of course I did. Meco snuck into that puzzle, too. But that's a story of other galactic funk.

Filling the grid in The Age of Search

I use a crossword creator program (Puzzle Maker for Mac by Hokua Software LLC) to produce a puzzle grid that includes all (or virtually all) the core terms I'm hoping to get into a puzzle. The program builds several grids and allows me to choose. Computers are good at constructing a grid with lots of crossed words. Still though, it spends a few minutes concocting the options. That initial puzzle, with about 50 terms on a 28 x 28 grid, has too much empty space for my liking.

I'm no Will Shortz. (There's only one Will Shortz and he's a national treasure.) But I do feel a compulsion to fill in that grid with additional words. With an initial puzzle already built, the words I add have to fit specific places on the grid. Second letter E and fifth letter L, and so on.

There are web pages designed to find words that match the criteria. Sometimes the criteria are too tough: no matches. Sometimes they're too easy: 672 matches. This is the process that consumes the bulk of the puzzle-building time.

I usually begin scoping out the puzzle to see if I can add planet names. Or terms from previous chapters. Or math. When the going gets tough (near the end) and only two-letter "words" will do, state abbreviations and chemical symbols come in handy. As do Roman numerals, to be honest.

Sometimes a three-letter term is needed to bridge a gap. Government agencies are useful there. And some of the word-clue combos are essentially giveaways: three-letter term for Universal Serial Bus. Is it still instructive? Not everybody knows what USB or URL stands for. So there's that. Initialism are handy. Acronyms are nice, too: SCUBA and LASER come to mind. (Not everybody knows initialisms and acronyms are different things.)

In the end, I usually and up with a puzzle that has more than a hundred words that cross in over 150 places. Compare that to all the other puzzles you see for use in the classroom. Honestly: any of them! They might have two dozen words that cross in three dozen places. But they'll nearly always have enough open space to grow crops in. That was understandable in the 1970s. But now we have computers and the Internet. Machines are great at coming up with busy grids and words that will fill the spaces.

Would AI come up with a better puzzle? Maybe. I'm sure it could fill more of the 28 x 28 grid than I do. But would the words be appropriate for high school science students? Would those gap-filler words be matched to the intended audience? I haven't tried any AI crossword puzzle generators.

I design puzzles that take time to solve completely. Collaboration may be helpful. The Internet knows the answer to each individual clue (I think). But it's going to take a while, no matter how you solve it.

Fun use case: give a puzzle to students with no Internet access and see how it goes. Let them collaborate. I'm confident that a room full of high school science students could solve any of my puzzles. Eventually.

More standard use case: give the next unit's puzzle to students as they turn in unit tests with time to spare. My unit tests tended to be short enough that average students would have time left in the hour. They had to work quietly on something. My crosswords were a nice way to spend this minutes. And even though they weren't yet familiar with the next unit's academic vocabulary, half the terms in the crossword were terms they might already know. And the exercise gave them a preview of the new words to be learned soon.

Print or Online: Whatever Works for You

I used crossword puzzles in class in The Before Times, so I printed and photocopied them. When lockdowns hit, the importance of online options became apparent. The Before Times aren't coming back, so my crossword puzzles are printable and uploadable for use online. To implement the online option, you need to upload the HTML folder to your server space, then share the resulting web address (URL) with students. I uploaded a few to my own server space so you can see how they play online. They work well on laptops and tablets; not so well on phones.

Word List And Partially Solved Options

Each puzzle includes a Word List text file and PDF that can be printed and photocopied or shared electronically. Additionally, I included PDFs of "partially solved" puzzles. Grade-level puzzles include student documents with 10% and 20% of the letters filled in in advance. For AP Physics, the pre-solves are 5% and 10%.

Me? I didn't give students the word list or partially solved puzzles. But the options are there for you. Your students; your call!

Crossword puzzles at The Lessons of Phyz

Chemistry Crossword Puzzles [OpenStax-aligned]

I finished sets of crossword puzzles for Physics and AP Physics (1 & 2). But creating crossword puzzles is so much much fun, I wandered the Internet over to OpenStax and found their Chemistry textbook. The first chapter had an end-of-chapter vocabulary list. So away I went. This post will be updated as new chemistry crosswords are added to the collection.

The Lessons of Phyz crossword advantage? At least 100 words that cross at least 150 times. Not those mostly empty grids with a handful of words and two dozen crosses. I'm no Will Shortz, but I am putting in some effort. And while the majority of the terms are chemistry, science, and math-related, the occasional Taylor Swift, Disney, or other pop culture references work to engage students that might be otherwise less engaged in the course. My own students used to gobble up crossword puzzles even without any promise of reward. Conquering the grid was all the incentive they needed.

1. Essential Ideas at TPT [Free]

Word Count: 103 · Puzzle Score (word crosses): 158

Core terms:Accuracy, Atom, Celsius, Centimeter, Change, Chemical, Chemistry, Compound, Conservation, Conversion, Cubic, Density, Element, Exact, Extensive, Fahrenheit, Gas, Heterogeneous, Homogeneous, Hypothesis, Intensive, Kelvin, Kilogram, Law, Length, Liquid, Liter, Macroscopic, Mass, Matter, Meter, Microscopic, Milliliter, Mixture, Molecule, Physical, Plasma, Precision, Property, Pure, Rounding, Second, SI, Significant, Solid, Temperature, Theory, Uncertainty, Unit, Volume, Weight

Selected additional terms: Acute, Amber, Andromeda, cc, Cone, cos, Divide, Echo, Etna, GMO, Gram, HIV, Hue, Inch, Neptune, Odor, Parallel, Perpendicular, sin, Sodium, Spine, TNT, Venus

BONUS: Online Version of "Essential Ideas" Chemistry Crossword

2. Atoms Molecules Ions at TPT

Words: 103 · Puzzle Score: 159

Advanced Placement Crossword Puzzles

That's right. Physics crosswords suitable for AP Physics students. Topical terms constitute the core of the word list. Unlike the first series, there are no “words all high school students should know” vocabulary terms. Fill-in terms lean toward physics and science, but sometimes wander into pop culture or randomness. 

One nice thing about crosswords is that students know what to do with them without any instructions. They take to the challenge right away. The students who enjoy them most are often students who don't seem to enjoy the class the most. 

Note: the "puzzle score" stat listed in each puzzle's description indicates the number of word crosses/intersections. If you look at other crosswords at TPT or elsewhere, they typically involve a few dozen (sometimes one dozen) words with a few dozen crosses. Lessons of Phyz crosswords tend to involve more than 100 words with 150+ crosses. I begin each puzzle with core typical words, then fill in the gaps with terms from, physics, science, pop culture, and randomness. I intend to fill the grid without making something that will require more than two pages.

AP PHYSICS 1

An AP1 Physics Crossword Puzzle Bundle includes all three of the following.

Motion and Forces at TPT

110 words with a puzzle score of 171. This is the first crossword of the year for the AP Physics 1 class. It covers kinematics, Newton's laws, circular motion and gravity. Core terms: Acceleration, Arc, Aristotle, Average, Body, Brahe, Brake, Centripetal, Change, Circular, Copernicus, Deceleration, Distance, Drag, Earth, Ellipse, Force, Friction, Galileo, Gas, Gravitational, Inclined, Inertia, Instantaneous, Interval, Kepler, Kilogram, Launch, Laws, Mass, Meter, Mu, Newton, Normal, Opposite, Pairs, Plane, Position, Projectile, Ptolemy, Pulley, Rate, Rest, Scalar, Speed, Steering, Sum, Tangential, Tension, Terminal, Uniform, Unit, Vector, Velocity, Weight.

Energy and Momentum at TPT

127 words with a puzzle score of 182. The core words come from these conserved quantities. Additional words begin from motion and forces before going to other fields. Core terms: Bounce, Bullet, Collision, Conservation, Daughter, Elastic, Energy, Explosion, Fd,  Flex, Force,  GW, Half, Height, Impact, Impulse, Inelastic, Joule, kgms, Kinetic, Mass, mgh, Momentum, mv, Potential, Power, Speed, Speed, Square, Stable, Target, Time, Unstable, Velocity, Watt, Work. 

Additional terms include Acceleration, Apex, Areas, Atom, Axis, Centripetal, Deceleration, Drag, Earth, Ellipse, Equal, Friction, Galileo, Gravity, Hot, Ideal, Inertia, Kelvin, Kepler, Kilogram, Kinematics, Lab, Laser, Log, Mercury, Meter, Nano, Newton, Normal, Nu, Opposite, Orbs, Ovum, Pair, Pattern, Petri, Pi, Rest, Rev, Second, Solid, Star, Tension, Tera, Tesla, Uniform, Universal, Waves, Weight.

Vibration and Rotation at TPT

121 words with a puzzle score of 189. The core words come from harmonic motion and rotational mechanics. Additional terms come from force, motion, energy, and momentum. Core terms: Acceleration, Alpha, Amplitude, Angular, Arm, Axis, Balance, Conservation, Constant, Cylinder, Degrees, Displacement, Elastic, Energy,  Force, Frequency, Fulcrum, Harmonic, Hollow, Hooke, Hoop, Inertia, Kinetic, kx, Length, Lever, Mass, Maximum, Minimum, Momentum, Omega, Parallel, Pendulum, Period, Potential, Radian, Ratio, Resonance, Restoring, Revolutions, Rotational, sin, Solid, Sphere, Spring, Standing, Tau, Top, Torque, Velocity. 

Selected additional terms: Centripetal, Collision, Deceleration, Earth, Ellipse, Fusion, Gram, Gravitational, Impact, Kilo, Luna, ma, Meter, mgh, Nano, nm, N/m, Nrg, Opposite, Peta, Pi, Pluto,  RGB,  Saturn, Slow, Tension, Uranus, Venus, vt.

AP PHYSICS 2

An AP2 Physics Crossword Puzzle Bundle includes all five of the following.

Mechanics Review at TPT

113 words with a puzzle score of 166. At the beginning of the year of AP Physics 2, we spend time reviewing the common mechanics topics covered in grade-level Physics and AP Physics 1. AP2 presumes knowledge of these topics, but we won't cover them formally in AP2. This crossword is part of this review process. Core terms: Acceleration, Action, Arc, Centripetal, Collision, Components, Conserved, Direction, Drag, Earth, Elastic, Ellipse, Energy, Equal, Explosion, External, Force, Friction, Fun, Galileo, Gravity, Horizontal, Impact, Inelastic, Inertia, Interaction, Inversely, Joule, Js, kg, kgms, Kilo, Kilogram, Kinetic, Mass, Mechanical, Meter, Momentum, ms, Mu, Net, Newton, Nm, Normal, Opposite, Orbit, Parabola, Power, Projectile, Relative, rev, Run, Second, Speed, Spring, Square, Tangential, Tension, Uniform, Unit, Universal, Velocity, Watt, Weight, Work.

Fluids and Thermodynamics at TPT

105 words with a puzzle score of 150. The core words come from fluid mechanics and thermodynamics. Core terms: Absolute, Adiabatic, Archimedes, Area, Bernoulli, Buoyant, Carnot, Cold, Conductivity, Continuity, Cycle, Density, Depth, Displacement, Efficiency, Energy, Engine, Entropy, Float, Fluid, Force, Gauge, Heat, Hot, Impulse, Isobaric, Isothermal, Isovolumic, Joule, Kelvin, kPa, Law, Pascal, Pressure, Sink, Temperature, Thermal, Torricelli, Volume, Wind, Work.

Selected additional terms: Amplitude, Charge, cos, Cyan, Deceleration, Dipole, Ear, Echo, Elements, Gravity, Hertz, Inertia, Luna, Node, Omega, Orca, Oxygen, Petals, Radical, Rate, Rougher, Senses, Series, sin, Sleep, Sound, Spectrum, Tesla, Test, Tnt, Torque, USB, Velocity, Wavelength, Zinc.

Electricity and Magnetism at TPT

114 words with a puzzle score of 174.  The core terms come from electrostatics, circuits, and magnetism. Core terms: Ampere, As, Attract, BA, Battery, Capacitor, Charge, Circuit, Conduction, Conductor, Coulomb, Current, Destructive, Dipole, Domain, Electrons, Electrostatic, Energizes, Energy, Faraday, Field, Flux, Force, Franklin, Generator, Glass, Induction, Insulator, IR, Kirchhoff, Magnet, Motor, Negative, Neutral, Oersted, Ohm, Open, Parallel, Polarized, Pole, Positive, Potential, Power, Proton, Repel, Resistance, Resistor, Semiconductor, Series, Short, Silk, Superconductor, Tesla, Volt, Voltage, Watt, Weber.

Optics at TPT

116 words with a puzzle score of 177. The core terms come from geometric (ray) optics and physical (wave) optics.mCore terms: Angle, Blue, Center, Central, Chartreuse, Concave, Cone, Constructive, Converging, Convex, Critical, Destructive, Diffraction, Diffuse, Dispersion, Diverging, Enlarged, Focus, Frequency, Glare, Height, Image, Incident, Index, Interference, Internal, Inverted, IR, Iridescence, Laser, Lens, Light, Magnification, Maxima, Minima, Mirror, Nano, Nitrogen, nm, Normal, Object, Optics, Order, Plane, Polarization, Radius, Rainbow, Ray, Real, Red, Reduced, Reflection, Refraction, Rod,  Screen, Slit, Snell, Specular, Ultraviolet, Upright, Violet, Virtual, Wavelength, Xray.

Atomic and Nuclear Physics at TPT

121 words with a puzzle score of 177. The core terms come from atomic and nuclear physics. Additional terms come from mechanics, fluids, thermodynamics, electricity and magnetism, and optics. Core terms: Absorption, Atomic, Beta, Bohr, Chain, Charge, Critical, Curie, Dating, DeBroglie, Defect, Duality, Effect, Einstein, Electron, Emission, Energy, eV, Fission, Frequency, Function, Fusion, Gamma, Ground, Half, Hertz, hf, Ionize, Kinetic, Light, Momentum, Neutron, Nucleon, Nucleus, Number, Phi, Photoelectric, Photon, Planck, Proton, Quantum, Strong, Tension, Time, TOE, UV, Wavelength.

Physics Crossword Puzzles [Conceptual Physics]

Once I gained access to crossword puzzle creation software, I plied computer power to generate physics-themed puzzles. The trouble with most academic crosswords is that they consist one or two dozen words, not that many crosses, and a whole lot of empty "zen space". 

I was determined to fill the gaps on my physics crosswords with other terms, preferably science terms. When you get deep into gap-filling, you appreciate the value of short words, acronyms, and initialisms. Later I got the idea using words from online lists of "words all high school students should know". I knew that would bring some joy to the hearts of my ELA colleagues.

The puzzle-creation software package I initially used did not survive the 2000s. The most recent program I used still operates in the current version of the macOS operating system. So now I'm preparing crosswords for posting at TPT (Teachers Pay Teachers).

Puzzle Maker by Hokua Software LLC allows the creation of printable crosswords. It also allows for the creation of HTML puzzles that can be uploaded to one's server space and solved online. It also lets you drop in an image for the grid's backdrop rather than just using black, white, or gray. 

And for the printable PDF versions, I've prepared one with an empty grid, another with 10% of the letters prefilled, and another with 20% of the letters prefilled. Users can determine which level of difficulty is best for their students. I include a separate Word List for instructors to deploy at their own discretion. Words like "rarefaction" and "specular" are likely to show up where appropriate, as will high school vocab words like "impetuous" and "evanescent," so hints can prove useful.

I've discovered that there is much more craft involved in the creation of a robust, "busy" crossword puzzle, even with computer power. This is why so many subject-matter crosswords are so sparse.

Physics Crossword Puzzles at TPT