suggest an explanation for the ideal nature of helium compared to the other gases
2 electrons fit it that first shell. Helium has exactly 2, no extras and not short any. Therefore He does not want to combine with other atoms, including another He to form a chemical compound or molecule. Therefore called "noble".
Hydrogen for example has ONE electron in the shell that would hold 2 and is therefore likely to react with other atoms, even another H to form H2 but Helium gas is He NOT He2
The ideal nature of helium is attributed to its unique physical and chemical properties compared to other gases. To understand why helium is considered ideal, let's explore its characteristics and how they contribute to its ideal behavior.
1. Atomic Structure:
Helium is a noble gas with an atomic number of 2, meaning its nucleus contains two protons. It has the simplest atomic structure among all gases, consisting of only two electrons orbiting its nucleus. This simplicity contributes to its stability and inertness, making helium less likely to react with other substances.
2. Monatomic:
Unlike many other gases that exist as diatomic molecules (such as oxygen, nitrogen, and hydrogen), helium exists as single atoms. This monoatomic nature increases its independence and reduces the possibility of intermolecular forces, resulting in a more ideal behavior.
3. Low Boiling and Freezing Points:
Helium has the lowest boiling point (−268.93°C or −452.07°F) and the lowest freezing point (−272.20°C or −457.96°F) among all elements. These extremely low temperatures allow helium to remain in a gaseous state even at very low temperatures, making it an ideal coolant for various applications, including superconductor technology.
4. Low Molecular Weight:
With a molecular weight of 4 atomic mass units (amu), helium is the lightest of all gases. Its low molecular weight allows helium atoms to move more freely and at higher speeds compared to heavier gases. This property makes helium highly diffusive, meaning it can quickly spread and disperse in different environments.
5. Low Density:
Helium is less dense than air, making it lighter than the surrounding atmosphere. This characteristic makes helium buoyant, allowing it to rise upwards. This property is why helium is used in balloons, as it provides an uplifting force, causing the balloon to float.
6. Non-toxic and Inert:
Helium is non-toxic and chemically inert. It does not react with most other elements, making it safe to inhale in small amounts (although caution should be exercised as helium displaces oxygen in the lungs). Its inertness also makes helium suitable for various applications, such as as a shielding gas in welding or as a carrier gas in analytical instruments.
In summary, the ideal nature of helium can be attributed to its simple atomic structure, monatomic nature, low boiling and freezing points, low molecular weight, low density, non-toxicity, and inertness. These unique properties make helium versatile and widely used in various scientific, medical, and industrial applications.