Cathode ray

High school (ages 12+)
Science & Technology

Name:

Date:

Step 1 · Read the article

Open the article and read it at the level above. Then answer the questions below in your own words.

https://smallwhale.org/articles/cathode-ray

Write what each word means, using the article.

Do not copy the article. Write two things you learned, the way you would explain them to a friend.

Answers below are taken from the article’s stored facts, so they match what the student read.

1. What is the primary technological application?Cathode Ray Tubes (CRTs) for visual displays in televisions, monitors, and oscilloscopes
2. What is the underlying physics?Fundamental to the development of atomic physics, quantum mechanics, and electronics
3. Who first saw cathode rays and when?German scientists Julius Plücker and Johann Wilhelm Hittorf first saw cathode rays in 1859 while studying electricity in a glass tube.
4. How did J.J. Thomson prove cathode rays are particles?In 1897 Thomson used electric and magnetic fields to bend the rays and measured their charge‑to‑mass ratio, showing they were small, negatively charged particles.

Electron: A stable subatomic particle with a negative elementary electric charge, a fundamental constituent of matter.
Cathode Ray Tube (CRT): A vacuum tube containing a phosphorescent screen and an electron gun, used to display images by scanning electron beams.
Charge-to-Mass Ratio: A physical property of a particle, representing the ratio of its electric charge to its mass, crucial in Thomson's electron discovery.
Phosphor: A luminescent substance that emits light when excited by radiation, such as an electron beam in a CRT.