Cesium

Cesium is a chemical element with the symbol Cs and atomic number 55. It is a soft, silvery-gold alkali metal with a melting point of 28.5 °C (83.3 °F), which makes it one of only five elemental metals that are liquid at or near room temperature. Cesium is an extremely reactive metal and is pyrophoric, meaning it can spontaneously ignite when it comes into contact with air.

Properties of Cesium:

• Atomic number: 55
• Symbol: Cs
• Atomic mass: 132.91
• Melting point: 28.5 °C (83.3 °F)
• Boiling point: 671 °C (1,240 °F)
• State at room temperature: Solid (but melts very easily)
• Reactivity: Highly reactive

Uses of Cesium:

Cesium has several important uses, including:

1. Atomic clocks: Cesium is used in atomic clocks, which are the most accurate time and frequency standards.
2. Petroleum exploration: Cesium vapor is used in devices called magnetometers to measure changes in the Earth's magnetic field, which can help locate oil and gas deposits.
3. Catalysts: Cesium-based compounds are used as catalysts in organic synthesis.

Study Guide:

1. What is the atomic number of cesium?

   The atomic number of cesium is 55.

2. What is the melting point of cesium?

   The melting point of cesium is 28.5 °C (83.3 °F).

3. What are the main uses of cesium?

   The main uses of cesium are in atomic clocks, petroleum exploration, and as catalysts in organic synthesis.

[Cesium] Related Worksheets and Study Guides:

• Elements and the periodic tableScience • Seventh Grade
• Elements, mixtures and compoundsScience • Fifth Grade