Definition

A soft, silvery metal that is very reactive and has the atomic number 55. It is part of the alkali metal group and can be found in small amounts in certain rocks and minerals.

Example

Caesium is used in atomic clocks due to its precise frequency.

Conversation

Have you heard about the element caesium?

Yeah, it's pretty interesting; it’s highly reactive, right?

Exactly! I read that it can even explode on contact with water.

That's wild! I never knew an element could be so dangerous.

Synonyms & Antonyms

Root Explanation

Caesium comes from the Latin word 'caesius' (meaning sky blue or gray), which refers to the blue lines in its spectrum. The name reflects the color of the light emitted by the element when it is heated.

Memory Tip

Think of the Latin word 'caesius' meaning sky blue, which helps you remember that caesium is named for the blue color seen in its spectrum.

Visually Confused Words