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Date: 2-1-2018
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Date: 1-4-2019
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Date: 12-1-2018
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Helium is the second most abundant element in the universe, next to hydrogen. Helium is colorless, odorless, and tasteless. It has a very low boiling point, and is monatomic. Helium is small and extremely light, and is the least reactive of all elements; it does not react with any other elements or ions, so there are no helium-bearing minerals in nature. Helium was first observed by studying the sun, and was named after the Greek word for the sun, Helios.
Physical Properties
Color | Colorless |
Phase at Room Temperature | Gas |
Density | 0.0002 g/cm3 |
Boiling Point | 4.2 K |
Heat of Vaporization | 0.1 kJ/mol |
Thermal Conductivity | 0.15 J/m sec K |
Source | Natural gas |
Atomic Properties
Electron Configuration | 1s2 |
Number of Isotopes | 7 (2 liquid) |
Electron Affinity | 0 kJ/mol |
First Ionization Energy | 2372.3 kJ/mol |
Second Ionization Energy | 5250.3 kJ/mol |
Polarizability | 0.198 Å3 |
Atomic Weight | 4.003 |
Atomic Volume | 27.2 cm3/mol |
Atomic Radius | 31 pm |
Abundance
In Earth's Crust | 8x10-3 |
In Earth's Ocean | 7×10-6 |
In Human Body | 0% |
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