Helium

Definition

Helium is a colorless, odorless, and inert gas that is the second lightest and second most abundant element in the universe. It is primarily produced through nuclear fusion in stars and plays a significant role in the chemical composition of the atmosphere, albeit in trace amounts compared to other gases. Helium’s unique properties make it essential for various applications, including cryogenics and as a lifting gas in balloons.

5 Must Know Facts For Your Next Test

1. Helium constitutes about 0.0005% of the Earth's atmosphere, making it one of the rarest elements found in the air.
2. It is produced naturally through the radioactive decay of heavy elements like uranium and thorium within the Earth.
3. Unlike other elements, helium does not form chemical bonds under normal conditions due to its complete electron shell.
4. Helium has the lowest boiling point of any element, at approximately -268.93°C (-452°F), which makes it invaluable for scientific applications.
5. The majority of helium used today is obtained from natural gas extraction, where it is found in concentrations up to 7%.

Review Questions

• How does the presence of helium in the atmosphere compare to other gases, and why is this significant?
  • Helium is present in trace amounts in the atmosphere at about 0.0005%, which makes it one of the least abundant gases compared to more prevalent ones like nitrogen (78%) and oxygen (21%). This low concentration is significant because it highlights helium's unique production process through stellar nucleosynthesis rather than terrestrial sources. The rarity of helium contributes to its high value and importance in various scientific and industrial applications despite its abundance in the universe.
• Discuss the role of helium in cryogenics and how its properties make it suitable for this field.
  • In cryogenics, helium plays a crucial role due to its extremely low boiling point and inertness. It remains a liquid at temperatures close to absolute zero, which is essential for cooling superconducting magnets and other materials that require ultra-cold temperatures for optimal performance. Helium's inability to solidify under normal atmospheric pressure further enhances its utility in these applications, allowing researchers to study phenomena at low temperatures without interference from solidification.
• Evaluate the implications of helium's limited availability on technological advancements and industries relying on this element.
  • The limited availability of helium poses challenges for industries reliant on it for various technological advancements, particularly in fields like medicine, aerospace, and physics research. As natural reserves diminish and extraction becomes more costly, alternatives or conservation strategies need to be explored to mitigate impacts on industries such as MRI machines that require helium for cooling purposes. Additionally, the rising demand for helium for ballooning and party supplies further exacerbates supply issues, prompting discussions about sustainable practices and recycling methods to ensure continued access to this essential resource.

Related terms

Noble gases: A group of chemical elements that are characterized by their lack of reactivity due to having a complete valence shell, which includes helium, neon, argon, krypton, xenon, and radon.

Atomic structure: The arrangement of protons, neutrons, and electrons in an atom, which determines the chemical properties of the element; helium has two protons and two electrons.

Cryogenics: The study and application of materials at extremely low temperatures, where helium is often used as a coolant due to its low boiling point.