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.

Properties of Helium

• Atomic Number: 2
• Atomic Symbol: He
• Atomic Weight: 4.0026
• Phase at Room Temperature: Gas
• Boiling Point: -268.9°C
• Melting Point: -272.2°C
• Density: 0.1786 grams/liter
• Non-flammable
• Inert

Uses of Helium

Helium has several important uses, including:

• As a coolant for nuclear reactors and to cool the magnets in magnetic resonance imaging (MRI) machines.
• In gas chromatography as a carrier gas for various types of detectors.
• In cryogenics, as a cooling medium for superconducting magnets in MRI machines and other medical and scientific equipment.
• In filling balloons, airships, and blimps due to its low density and non-flammability.
• In deep-sea diving to dilute the oxygen and nitrogen in the air mixture to reduce the effects of high pressure on the body.

Study Guide

Here are some key points to remember about helium:

1. Identify the atomic number, symbol, and atomic weight of helium.
2. Describe the physical properties of helium, including its phase at room temperature, boiling and melting points, and density.
3. Explain the inert and non-flammable nature of helium.
4. Discuss the important uses of helium in various applications, such as cooling, gas chromatography, and balloon inflation.
5. Explain the significance of helium in scientific and medical research, particularly in the field of cryogenics and MRI technology.

Understanding the properties and uses of helium is important for various scientific and industrial applications. Remember to review these key points and explore further examples of how helium is utilized in different fields.