Particle Diagram draws the particulate-level pictures used in AP Chemistry: atoms, ions and molecules in a box, spread out as a gas or solution, close together as a liquid or in rows as a solid, or packed in a lattice for an ionic solid or alloy. Choose up to four kinds of particle and how many of each, or draw a before box and an after box with an arrow between them for a reaction or a change of state. Each atom has a size and a gray shade, an ion carries its charge written in its middle, and a molecule is a center atom with outer atoms touching it, in shapes like Cl₂, H₂O or CCl₄.
The box of particles is always the same size, so four answer choices made one at a time line up on the page. A key beside the box shows each kind with the name you type, and it can go with the box, be left off, or be shown alone, so several answer choices can share one key.
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What is a particle diagram in chemistry?
A drawing of the atoms, ions or molecules in a sample, showing how many there are and how they are arranged. AP Chemistry uses them to ask students to represent a gas, a solution or a solid, or to pick which picture matches a substance.
How do I make four answer choices that line up?
Make each choice one at a time and copy it into your document. Particles always go in the same square box, whatever their state, so the choices come out the same size. Set the key to Key only to make one shared key for all of them.
Can I show a reaction, before and after?
Yes. Set Boxes to Before and after and give each kind a count for each box: 4 H₂ and 3 O₂ before, say, and 4 H₂O and 1 O₂ after. The two boxes are the same size with an arrow between them, which can have a short label such as “heat”, and share one key, so they work for conservation of mass and limiting reactant questions. Each box has its own state, so the same particles can also show a change of state, like a solid melting.
Can it show solids, liquids and gases?
Yes. Pick the box’s state: Gas spreads the particles out at random, Liquid settles them close together but jumbled at the bottom, and Solid packs them in rows at the bottom, all turned the same way. Keep the same particles and change only the state to compare the three.
Can I show an ionic solid or an alloy?
Yes. Choose Lattice, then Alternating for an ionic solid like NaCl, Substitutional for an alloy like brass, or Interstitial for one like steel, with small atoms in some of the gaps.
Can I put element symbols on the atoms?
No. Atoms are drawn as plain shaded discs, and ions show only their charge. Put names like “Na⁺ ion” or “CCl₄ molecule” in the key instead.
How do I type subscripts and superscripts in the key?
Type _ before a subscript and ^ before a superscript, with braces around more than one character: H_2O for H₂O, SO_4^{2-} for SO₄²⁻, Na^+ for Na⁺. They work in the key’s names and its note line, and in a link to the figure.
Can the key show each atom on its own, for writing formulas?
Yes. Set the key’s List to Each atom instead of Each particle and it shows every different atom once, drawn alone with its own name, rather than each molecule whole. An atom in two kinds of molecule, like the O in H₂O and CO₂, is listed once. Students can then work out each molecule’s formula from the box.
Can a kind of particle appear in the key but not in the box?
Yes. Give it a count of 0 and it is listed in the key only. The key’s note line can say what isn’t drawn, like “H₂O molecules are not shown”.
Chemistry Figures Particle Diagram