Atomic Number of Helium

Helium Atomic Number

Atomic Number of Helium is 2.

Chemical symbol for Helium is He. Number of protons in Helium is 2. Atomic weight of Helium is 4.002602 u or g/mol. Melting point of Helium is -272,2 °C and its the boiling point is -268,9 °C.

» Boiling Point » Melting Point » Abundant » State at STP » Discovery Year

About Helium

The name of this element takes source from the Greek word meaning the Sun, primarily because it was discovered by astronomers to be present in the Sun prior to its being detected on our planet. Known as the second most common element in the Universe (though it is quite rare on our planet), Helium is one of the Noble gases, which is not reactive and does not mix with other elements to create other chemical compounds. The boiling point of Helium is the lowest of the ones in all other elements in the Periodic Table. Helium is lighter than air and is used in balloons, airships, and similar kind of devices. It is also a very effective cooling agent which is used in medicine and industry. As a mixture with neon, helium is used in common scanning devices in modern technology.

Properties of Helium Element

Atomic Number (Z)2
Atomic SymbolHe
Group18
Period1
Atomic Weight4.002602 u
Density0.0001785 g/cm3
Melting Point (K)unknown
Melting Point (℃)-272,2 °C
Boiling Point (K)4.22 K
Boiling Point (℃)-268,9 °C
Heat Capacity5.193 J/g · K
Abundance0.008 mg/kg
State at STPGas
OccurrencePrimordial
DescriptionNoble gas
Electronegativity (Pauling) χno data
Ionization Energy (eV)24.58741
Atomic Radius31pm
Covalent Radius32pm
Van der Waals Radius140
Valence Electrons2
Year of Discovery1895
DiscovererRamsay and Cleve

What is the Boiling Point of Helium?

Helium boiling point is -268,9 °C. Boiling point of Helium in Kelvin is 4.22 K.

What is the Melting Point of Helium?

Helium melting point is -272,2 °C. Melting point of Helium in Kelvin is unknown.

How Abundant is Helium?

Abundant value of Helium is 0.008 mg/kg.

What is the State of Helium at Standard Temperature and Pressure (STP)?

State of Helium is Gas at standard temperature and pressure at 0℃ and one atmosphere pressure.

When was Helium Discovered?

Helium was discovered in 1895.


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