Hydrogen

1
H
Group
1
Period
1
Block
s
Protons
Electrons
Neutrons
1
1
0
General Properties
Atomic Number
1
Atomic Weight
1.00794
Mass Number
1
Category
Other nonmetals
Colour
Colorless
Radioactive
No
From the Greek word hydro (water), and genes (forming)
Crystal Structure
Simple Hexagonal
History
Henry Cavendish was the first to distinguish hydrogen from other gases in 1766 when he prepared it by reacting hydrochloric acid with zinc.

In 1670, English scientist Robert Boyle had observed its production by reacting strong acids with metals.

French scientist Antoine Lavoisier later named the element hydrogen in 1783.
Electrons per shell
1
Electron Configuration
1s1
H
Hydrogen is the primary component of Jupiter and the other gas giant planets
Physical Properties
Phase
Gas
Density
0.00008988 g/cm3
Melting Point
14.01 K | -259.14 °C | -434.45 °F
Boiling Point
20.28 K | -252.87 °C | -423.17 °F
Heat of Fusion
0.558 kJ/mol
Heat of Vaporization
0.452 kJ/mol
Specific Heat Capacity
14.304 J/g·K
Abundance in Earth's crust
0.15%
Abundance in Universe
75%
Vial
Image Credits: Images-of-elements
Vial of glowing ultrapure hydrogen
CAS Number
1333-74-0
PubChem CID Number
783
Atomic Properties
Atomic Radius
53 pm
Covalent Radius
31 pm
Electronegativity
2.2 (Pauling scale)
Ionization Potential
13.5984 eV
Atomic Volume
14.4 cm3/mol
Thermal Conductivity
0.001815 W/cm·K
Oxidation States
-1, 1
Applications
Liquid hydrogen is used as a rocket fuel.

Hydrogen is commonly used in power stations as a coolant in generators.

Hydrogen's two heavier isotopes (deuterium and tritium) are used in nuclear fusion.

Used as a shielding gas in welding methods such as atomic hydrogen welding.
Hydrogen poses a number of hazards to safety, from fires when mixed with air to being an asphyxiant in its pure form
Isotopes
Stable Isotopes
1H, 2H
Unstable Isotopes
3H, 4H, 5H, 6H, 7H