Helium

Helium is a chemical element with the symbol He and atomic number 2. It is a colorless, odorless, tasteless, non-toxic, inert, monatomic gas that heads the noble gas group in the periodic table. Its boiling and melting points are the lowest among the elements and it exists only as a gas except in extreme conditions.

Atomic Structure

• Atomic number: 2
• Atomic symbol: He
• Atomic mass: 4.0026 u
• Electron configuration: 1s²

Properties of Helium

Helium has several unique properties, including:

• It is the second lightest element and is the second most abundant element in the observable universe.
• It has the lowest boiling point of all the elements, making it useful in cryogenics and for cooling superconducting magnets.
• It is used in gas chromatography, as a gas for supersonic wind tunnels, and as a filler for balloons and airships due to its low density.
• Helium is non-flammable and is often used as a safe alternative to hydrogen in applications such as airships and balloons.

Uses of Helium

Helium has a variety of important uses, including:

• As a coolant in nuclear reactors and in cryogenics for cooling infrared detectors, nuclear reactors, and the Large Hadron Collider at CERN.
• In the aerospace industry for purging and pressurizing, and as a lifting gas for balloons and airships.
• In the medical industry for cooling magnets in MRI machines and for use in respiratory treatments.
• In the electronics industry for cooling and pressurizing during the production of semiconductors and fiber optics.

Study Guide

Here are some key points to remember about helium:

1. What is the atomic number of helium?
2. What is the electron configuration of helium?
3. What are some unique properties of helium?
4. What are the uses of helium in various industries?

Understanding the properties and uses of helium is important for various scientific and industrial applications. It is also an interesting element to study due to its unique characteristics and widespread use.