To estimate the boiling point of Oganesson by extrapolating the data for the boiling points of the other noble gases.
The boiling points of the noble gases are given below:
Helium -269oC
Neon -246oC
Argon -186oC
Krypton -153oC
Xenon -108oC
Radon -62oC
Make a nicely labeled graph of boiling point vs. number of electrons. Using this graph, extrapolate your data to make a prediction for the boiling point of oganesson.
A brief explanation of why this method can be used to make a reasonable estimate of the boiling point of oganesson. Your explanation should include a description of the intermolecular forces that are present in samples of these elements, and how they affect their boiling points.
The correct answer and explanation is :
Estimated Boiling Point of Oganesson (Og): ~34°C
Explanation:
To estimate the boiling point of oganesson, we plotted the boiling points of noble gases against their number of electrons and extrapolated the trend. The noble gases—helium, neon, argon, krypton, xenon, and radon—show an increasing boiling point as their atomic number rises. The linear trend suggests that oganesson, with 118 electrons, is likely to have a boiling point around 34°C.
Intermolecular Forces and Boiling Points of Noble Gases
Noble gases are monatomic and interact only through London dispersion forces (van der Waals forces), which arise due to temporary dipoles in atoms. These forces increase with:
- Atomic Size: Larger atoms have more electrons that are more easily polarizable, leading to stronger dispersion forces.
- Number of Electrons: More electrons mean stronger induced dipoles, which results in higher boiling points.
Helium, the smallest noble gas, has very weak London forces, so it boils at -269°C. In contrast, radon, with much larger atomic size and more electrons, boils at -62°C. The trend suggests that oganesson, being even larger, should have an even higher boiling point.
Why This Method Works
By observing the systematic increase in boiling points with atomic size, we can use extrapolation to estimate the value for oganesson. Since the increase appears to follow a near-linear trend, a straight-line fit provides a reasonable estimate. The prediction of ~34°C indicates that oganesson may be a liquid at room temperature, unlike the other noble gases, which are all gases under standard conditions.
This estimation aligns with theoretical predictions, which suggest that relativistic effects in oganesson could further enhance London dispersion forces, making it behave more like a heavy semi-metallic element than a typical noble gas.