Periodic System for Chemists
Table
1
1.01

H

Hydrogen

Identification

CAS Number: 1333-74-0
Discovery Year: 1766
Discoverer: Henry Cavendish
Discovery Location: England

Properties

Atomic Mass: 1.008 →Density: 0.000082 g/cm³ →
Crust Abundance: 1400 mg/kg
Crystal Structure: HEX

Atomic Dimensions

Atomic Radius: 25 pm →
Atomic Radius (Rahm): 154 pm
Covalent Radius: 31 pm →
Van der Waals Radius: 110.00000000000001 pm
Atomic Volume: 14.1 cm³/mol
Lattice Constant: 3.75 Å

Thermodynamics

Melting Point: 14.01 K →Boiling Point: 20.28 K →Thermal Conductivity: 0.1815 W/(m·K) →Heat of Fusion: 0.117 kJ/mol →Heat of Vaporization: 0.904 kJ/mol →
Heat of Formation: 217.998 kJ/mol

Electronic Structure

Electron Config: 1s
Block: s
Period: 1 →Group: 1 →Electronegativity: 2.2 →Electron Affinity: 0.754195 eV →
Oxidation States: -1, +1

Abundance & Geochemistry

Crust Abundance: 1400 mg/kg
Sea Abundance: 108000 mg/L
Geochemical Class: volatile
Goldschmidt Class: atmophile

About

Hydrogen is the lightest and most abundant element in the universe. It is a colorless, odorless gas that combines with oxygen to form water.

Isotopes

H-1 1 99.97%
H-2 2 0.0280%