INTRODUCTION
Helium is a unique gas that only form liquid on cooling while other elements become solids, it only form a solid under higher pressure (about 25atm).It has the lowest boiling point of any liquid.
Helium is the second most abundant element in the universe, after hydrogen. The name comes from the Greek word helios, meaning 'Sun.' Sir Ernest Rutherford showed that alpha particles are the nuclei of helium atoms.
BASIC INFORMATIONS
- Atomic Number
- 2
- Atomic Mass
- 4.0026
- Atomic radius
- 0.12
- Ionization energy
- 2372
- Electronic config
- 2
- Principal Valency
- 0
- Density g/cm³
- 0.00021
- Melting point °C
- -272.2
- Boiling point °C
- -268.93
- Type of Element
- non-metal
- Electronegativity
- N/A
- Element Category
- Noble Gas
- Appearance
- Colourless Gas
- Block
- p-block
- Period
- 1
- Group
- 18
- No of Isotopes
- 8
- Occurrence
- Free Element
- Abundance in ppm
- 0.00052% 0f atm
- Year of Discovery
- 1895
EXTRACTION
It is extracted by the fractional distillation of liquid air
OXIDATION STATES
N/A
MAJOR SOURCE
Air
EXAMPLES OF COMPOUND PRESENT
N/A
ECONOMIC IMPORTANCE
* It is used to obtain the very low temperatures required for super conductivity and lasers.
* It is used in preference to dinitrogen to dilute dioxygen in the gas cylinders used by divers.
* It is used in discharge tubes to give variety colour and in weather balloons as well as airships.
* It is used in inert-gas arc welding for light metals, such as aluminum and magnesium alloys, that might otherwise oxidize;the helium protects heated parts.
