Make your own free website on Tripod.com
[ATOM]

Helium

[ATOM]
Information valid for He-4 unless otherwise noted

Basic Information


Symbol: He
Atomic Number: 2
Mass: 4.002602
Melting Point: -272.0 C
Boiling Point: -268.6 C
Number of Protons/Electrons: 2
Number of Neutrons: 2
Classification: Noble Gas
Crystal Structure: Hexagonal
Density @ 293 K: 0.1785 g/cm3
Color: colorless


Atomic Structure

[Bohr Model of Helium]
Number of Energy Levels: 1

  1. First Energy Level: 2

Isotopes

Isotope Half Life
He-3 Stable
He-4 Stable

Facts


Date of Discovery: 1895
Discoverer: Sir William Ramsey
Name Origin: From the Greek word hÍlios (sun)
Uses: balloons, deep sea diving
Obtained From: natural gas deposit, air