What is the Lewis Dot Structure?
In electron dot structures, the number of valence electrons for an element is represented as dots. According to the periodic table, valence electrons have the highest energy level.
The element symbol is used to represent an electron dot structure, and dots are added clockwise from the top of the element symbol until the desired number of valence electrons is reached. The maximum number of electrons that can be used is eight.
Table of Contents
Lewis Dot Structure of Helium
Helium is a noble gas with a complete valence shell. It is denoted by the symbol He.
Helium, unlike the other noble gases in Group 8, has only two valence electrons and the first orbit only has those two electrons. The electrons are represented as two lone pair dots in the Lewis symbol.
Chemical bonds are almost always formed by interactions of valence electrons in atoms. A simple way of representing valence electrons would be useful to aid our understanding of how they interact. Again, it makes no difference where the electron dots are placed on the symbol.
Properties of Helium
Physical Properties
| Melting Point | 0.95 K (or -272.2oC) |
|---|---|
| Boiling Point | 4.222 K (or -268.928oC) |
| Density | 0.1786 g/L at STP; 0.145 g.cm-3 at its melting point |
| Critical Temperature and Pressure | 5.195 K; 0.227 MPa |
| Triple Point | 2.177 K; 5.043 kPa |
| Appearance (at STP) | Colourless gas |
Chemical Properties of Helium
| Electron Configuration | 1s2 |
|---|---|
| First Ionization Energy | 2372.3 kilojoules per mole |
| Second Ionization Energy | 5250.5 kilojoules per mole |
| Van der Waals Radius | 140 picometers |
| Enthalpy of Fusion | 0.0138 kilojoules/mole |
Uses of Helium
- Helium is primarily used in altitude research and meteorological balloons.
- In autogenous welding, it is used as an inert protective gas.
- It is the only cooler capable of dropping temperatures below 15K (-434oF).
- Helium is also used in the manufacture of germanium and silicon crystals.
- Helium is used in pipeline leak detection because of its ability to diffuse through solids much faster than air.
- This element is also used as a carrier gas in gas chromatography.
- Liquid helium has a wide range of applications due to its low melting point, including cryogenics, magnetic resonance imaging (MRI), and superconducting magnets.
Frequently Asked Questions on Helium Lewis Dot Structure
What is the electronic configuration of Helium?
The electronic configuration of Helium is 1s2.
Is helium classified as a noble gas?
Elements with already full shells and no electrons to lend are known as noble gases, and helium, the smallest of these, is thought to be the most inert.
How many dots would a helium Lewis dot structure have?
Helium, unlike the other noble gases in Group 8, has only two valence electrons. The electrons are represented as two lone pair dots in the Lewis symbol.
Does helium lose or gain electrons?
Helium has 2 electrons in its outermost shell and is stable, which means helium does not gain or lose electrons. It neither shares electrons with other atoms nor reacts with other elements.
What other elements have a similar lewis structure as helium?
Elements in group 2 have two valence electrons in their outermost shell. Therefore, the single atom of group 2 will have a similar lewis dot structure as helium. Unlike group 2 metals, helium does not react or lose electrons.
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