Atoms Crossword Puzzle

Print a criss-cross vocabulary crossword on atoms, from protons, neutrons and electrons to isotopes, ions and bonds.

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Atoms Crossword

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Answer key: Atoms Crossword

1Q2I3IUSO4ATOMICNU5MBERRTOKO6NUCLEUSPEE7ELECTRO8NUE9S10BLU11HYDROGENTENRLDOL12PROTON

Across 4 ATOMICNUMBER · 6 NUCLEUS · 7 ELECTRON · 11 HYDROGEN · 12 PROTON

Down 1 QUARK · 2 ISOTOPE · 3 ION · 5 MOLECULE · 8 NEUTRON · 9 SHELL · 10 BOND

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Inside the Atom 23

  • Attract To pull toward, as a plus charge does to a minus
  • Cloud Word for the fuzzy spread of an atom's light, minus-charged particles
  • Electron Negative particle, the least massive of an atom's three kinds
  • Elementary Word for a particle that is not made of anything smaller
  • Gluon Particle that holds together the three building blocks inside each particle of an atom's center
  • Hadron Family name for composite particles such as the two kinds in an atom's center
  • Hair A human one is about a million carbon atoms wide
  • Lepton Family of light particles to which the atom's negative particle belongs
  • Level Energy ___: one of the fixed steps of energy that an atom's negative particle can have
  • Neutral Word for an atom whose plus and minus charges match
  • Neutron Particle of an atom's core that is neither plus nor minus
  • Nucleon Shared name of the two kinds of particle packed in an atom's core
  • Nucleus The heavy core of an atom
  • Orbital Zone of space in which an atom's negative particle will probably turn up
  • Photon Smallest parcel of light, sent out or taken in when an atom moves between two fixed energies
  • Proton Particle with a plus charge in an atom's core
  • Quark One of three inside each particle of an atom's core
  • Repel To push away: what the plus charges packed in an atom's core do to one another
  • Shell Layer of an atom's negative particles
  • Strong The ___ force, most powerful of the four, holds matter's smallest pieces together
  • Subatomic Word for anything smaller than an atom
  • Valence Word for the outermost negative particles, the ones that join atoms together
  • Volume The center holds nearly all of an atom's mass and almost none of its ___

Counting and Naming Atoms 20

  • Anion Atom that has picked up extra light particles and so carries a minus sign
  • Atomic number Count of positive particles that names an element
  • Bismuth Element number 83, whose atoms break down so slowly that the effect is negligible
  • Cation Atom that has given up light particles and so carries a plus sign
  • Deuterium Form of the lightest element with one uncharged particle in its center
  • Helium Element number 2, with two positive particles in every atom
  • Hydrogen Simplest element, whose atom has one positive particle
  • Ion Atom left with a net charge, plus or minus
  • Isotope One of a family of atoms of an element with different masses
  • Nuclide Any one kind of atom's core, with a set count of each of its two particles
  • Oganesson Element number 118, the last of the known elements
  • Periodic The ___ table lists the elements in order of their positive particles
  • Picometer Unit for the width of an atom, which is typically about 100 of them
  • Protium Name of the form of the simplest element that has a mass number of 1
  • Radius Measure of an atom's size, from its center to its outer edge
  • Sum The mass number is this: both kinds of particle in the center, added up
  • Symbol Shorthand for an element, such as He or U
  • Tritium Form of the lightest element with two uncharged particles in its center
  • Twelve Mass number of the stable carbon atom with six uncharged particles
  • Uranium Element number 92, which exists only in unstable forms

Atoms Joined Together 24

  • Bond Chemical link between two atoms
  • Chemistry Field that deals with the changes made when atoms attach and detach
  • Compound Matter built from atoms of more than one element
  • Covalent Kind of link in which two atoms hold a pair of negative particles in common
  • Crystal Its name comes from a Greek word for ice; its atoms keep a strict order
  • Diamond Gemstone whose carbon atoms sit in a cubic structure that bears its name
  • Diatomic Word for a pair of atoms joined as one, such as H2
  • Double Kind of link made of two pairs of negative particles held in common
  • Eight Count of outermost negative particles that main-group atoms tend toward when they join
  • Formula H2O is one: it shows which atoms are in a unit and how many of each
  • Graphite Form of carbon that consists of many stacked layers
  • Inert Old word for the gases of the last column, which hardly react
  • Ionic Kind of link in which opposite charges hold atoms together
  • Lattice Regular, repeating framework of atoms in a solid
  • Metallic Kind of link in which each atom gives one or more negative particles to a shared sea
  • Molecule Group of atoms joined into a single unit, such as O2
  • Monatomic Word for a gas whose atoms stay single, such as argon
  • Noble The ___ gases, such as argon, almost never join with other atoms
  • Octet The ___ rule: atoms tend toward a full outermost layer of negative particles
  • Oxygen Element whose atoms pair up as O2
  • Plasma The solar wind is made of it, and it fills the space between the planets
  • Salt Table ___: charged atoms of two elements stacked in a regular pattern
  • Transfer Handing over of a negative particle from one atom to another
  • Water H2O: two atoms of one element joined to one of another

Radioactivity, Light and Energy 23

  • Absorb To soak up, as an atom does with radiation
  • Alpha Kind of radiation: two positive and two uncharged particles thrown out together
  • Becquerel Physicist, first name Henri, who found in 1896 that some matter gives off rays by itself
  • Beta Kind of radiation: the center gives out a negative particle or its positive twin
  • Big Bang Beginning of the Universe; in about three minutes it made most of the second-lightest element
  • Binding ___ energy: what makes the particles of an atom's center stay together
  • Clock What unstable carbon serves as, because it breaks down at a steady rate
  • Curie Marie ___, who showed that the rays of element 92 were a property of atoms
  • Dating Carbon ___: telling the age of old wood or bone from its unstable atoms
  • Decay Breaking down of an unstable core over time
  • Emit To send out light or other radiation: the reverse of taking it in
  • Excited Word for an atom whose negative particle has jumped to a higher energy
  • Fission Breaking of one large atomic core into smaller ones
  • Fusion Merging of small atomic cores into a bigger one, as in the Sun
  • Gamma Kind of radiation that carries no piece of matter away from the center, only a ray
  • Ground ___ state: the lowest energy of an atom's negative particle
  • Half-life Time in which 50 percent of a stock of unstable atoms changes into something else
  • Laser Tool whose one coherent beam comes from atoms giving off light in step
  • Nitrogen Element that carbon-14 turns into as it breaks down
  • Radioactive Word for an atom whose center breaks down by itself
  • Spectrum Pattern of light given off by an element, unique to it, by which it can be identified
  • Stars Where light atomic centers join, in a reaction that keeps itself going
  • Transmute To change one element into another

Models and Discoveries 22

  • Bohr Dane whose 1913 model let an atom's negative particles circle only at certain energies
  • Brownian ___ motion: the random jitter of tiny grains hanging in a liquid or a gas
  • Cathode ___ rays: the beams in which the atom's negative particle was found
  • Chadwick English discoverer of the uncharged particle in 1932
  • Dalton English scientist whose theory of atoms dates from the early 1800s
  • Democritus Greek thinker of the 400s BC who, with his teacher, developed an early idea of atoms
  • Einstein In 1905 he modelled the jiggling of pollen grains in a liquid as knocks from unseen particles
  • Foil Very thin leaf of metal, the target in the tests of 1908 to 1913
  • Geiger Physicist, first name Hans, who ran the scattering tests with Marsden
  • Gold Metal of the thin sheet in the most famous scattering test
  • Leucippus Greek philosopher of the 400s BC whose pupil shared his idea of atoms
  • Manchester English city whose university housed the scattering tests
  • Mendeleev He used his 1869 table to predict three elements nobody had yet found
  • Microscope Scanning tunneling ___: tool that lets single atoms be pictured
  • Moseley Physicist, first name Henry, who found in 1913 that an element's X-rays follow its place in the table
  • Nobel Award of 1935 that honored the finding of the uncharged particle
  • Planetary Word for a model in which negative particles circle the center like worlds round a sun
  • Pudding Plum ___: popular name of the 1904 model of the atom
  • Rutherford Leader of the team whose tests of 1908 to 1913 revealed the atom's tiny core
  • Schrödinger Austrian whose 1926 equation treats an atom's negative particles as waves
  • Thomson Discoverer of the atom's negative particle in 1897
  • Uncuttable What the Greek word atomos means

How this list was compiled: Clues written for this site for middle and high school science, in five sets after a basics set: inside the atom, counting and naming atoms, atoms joined together, radioactivity and light, and the models of the atom. Particles, isotopes and nuclei were checked against the DOE Explains pages of the U.S. Department of Energy (energy.gov), and the history, people and dates against English Wikipedia (CC BY-SA 4.0), in October 2026. Licence: own work

How it works

This printable atoms crossword puzzle fits Letter or A4, answer key included. The first puzzle has 12 basic words, among them Proton, Neutron, Electron, Nucleus, Shell, Isotope, Ion and Atomic number.

Read the full guide

Five sets after the basics

Inside the Atom has Gluon, Orbital, Valence and Lepton. Counting and Naming Atoms has Cation, Anion, Deuterium and Nuclide. Atoms Joined Together has Covalent, Ionic, Octet and Lattice. Radioactivity, Light and Energy has Half-life, Fission, Fusion and Spectrum.

A set for the story of the atom

Models and Discoveries goes from Democritus and the Greek word for Uncuttable to Dalton, Thomson and Cathode rays, Rutherford's Gold Foil, Bohr in 1913, Schrödinger in 1926 and Chadwick, who found the neutron in 1932.

  • Print Inside the Atom after the first lesson on atomic structure, and Models and Discoveries beside a timeline of atomic models.

Questions and answers

What grade is the atoms crossword puzzle for?

Atom Basics suits grades 6 to 8, with answers such as Proton, Shell, Molecule and Bond. The five themed sets use high school chemistry and physics vocabulary, such as Nuclide and Hadron. These bands are our judgment, not a published standard.

Does the atoms crossword puzzle come with an answer key?

Yes. Every print ends with the key on a sheet of its own, the grid filled in and the answers listed by clue number. It is free and needs no sign-up.

What are the three parts of an atom?

Protons and neutrons, packed in the nucleus, and electrons around it. Protons carry a positive charge, electrons a negative one, and neutrons none. All three are answers, so the clues name them by charge.

What is the difference between an isotope and an ion?

Isotopes are atoms of one element with different numbers of neutrons, so they differ in mass. An ion is an atom with more or fewer electrons than protons, so it carries a charge. Both words are in the first puzzle.

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