History of the atom timeline: what happened when?: timeline worksheet for Grade 11, page 1 preview

Timeline worksheet · Science

History of the atom timeline: what happened when? · Grade 11

Match 7 events about history of the atom to their dates on a timeline using an event bank. Practices chronology and reading a scaled timeline.

Grade 11 · ages 16 to 17
Medium
15 to 20 minutes
1 page
Free

The answer key is a separate page for grown-ups. Sign in to download it.

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The events

Directions: Each date on the timeline has a box. Write the letter of the event that happened then.

Events
Erwin Schrödinger publishes his wave equation describing electrons.
John Dalton presents his atomic theory:
each element has its own kind of atom.
C James Chadwick discovers the neutron.
Uranium nuclei are split; Lise Meitner and Otto
Frisch soon explain it as nuclear fission.
Democritus proposes that matter is made of tiny, indivisible atoms.
Niels Bohr proposes that electrons move in fixed energy levels.
J. J. Thomson discovers the electron using cathode rays.
oldest newest
about 400 BCE

What your child practices

Your child practices chronology and reading a scaled timeline.

Grades and ages: Grade 11, ages 16 to 17
Time: About 15 to 20 minutes
Subject: Science
Level: Medium for Grade 11
Answer key: Yes, for grown-ups who sign in
Printing: 1 page, US Letter or A4, low-ink option
Updated: October 15, 2026

How to use it

Try the first question together so the format is clear. Then let your child work through the rest, showing their thinking on the page. It is pitched at the expected level for Grade 11, for practice after the topic has been taught.

An answer key comes with it as a separate page that grown-ups download after signing in.

Tip for grown-ups: Find the oldest and newest events first, then fill in the middle.

Done on paper? A grown-up can record it on the child's page in PlayOwl; downloading alone doesn't count as finished.