HYDROGEN, H (1)

Hydrogen, the lightest chemical element, is a diatomic gas that is colourless, odourless, and flammable at room temperature.

ELEMENT BRIEF

1766, Henry Cavendish, England.

DISCOVERY

Ancient Greek, ὕδωρ (húdōr, 'water')
+ γεννάω (gennáō, 'I bring forth').

ETYMOLOGY

Hydrogen

ELEMENT

H

SYMBOL

1

ATOMIC NUMBER

1333-74-0

CAS NUMBER

ELEMENTAL SPECTRUM

Colourless

ELEMENTAL COLOUR

1.000'132

REFRACTIVE INDEX

-

POISSON RATIO

11.214 cm³

MOLAR VOLUME

-

BRINELL HARDNESS

-

MOHS HARDNESS

-

VICKERS HARDNESS

1,270 m/s, Mach 3.702'6

SPEED OF SOUND

-

BULK MODULUS

-

SHEAR MODULUS

-

YOUNG MODULUS

ALLOTROPES

14.01 K, -259.14 °C

MELTING POINT

20.28 K, -252.87 °C

BOILING POINT

808.65 K, 535.50 °C

AUTOMATIC IGNITION

255.15 K, -18.00 °C

FLASHPOINT

32.97 K, -240.18 °C

CRITICAL TEMPERATURE

1.29M Pa, 13 Atm

CRITICAL PRESSURE

0.180'500 W/(m K)

THERMAL CONDUCTIVITY

-

THERMAL EXPANSION

14,300.00 J/(kg K)

SPECIFIC HEAT

0.558 kJ/mol

HEAT FUSION

0.452 kJ/mol

HEAT VAPORISATION

-

HEAT COMBUSTION

-

CURIE POINT

-

NEEL POINT

7/5

ADIABATIC INDEX

Gas

PHASE

-

ELECTRICAL TYPE

-

CONDUCTIVITY

-

RESISTIVITY

-

SUPERCONDUCTING POINT

Diamagnetic

MAGNETIC TYPE

-0.000'000'024'8

MASS SUSCEPTIBILITY

-0.000'000'000'049'99

MOLAR SUSCEPTIBILITY

-0.000'000'002'23

VOLUME SUSCEPTIBILITY

Non Metal

CLASSIFICATION

1.007'940'8

ATOMIC WEIGHT

53 pm

ATOMIC RADIUS

32 pm

COVALENT RADIUS SINGLE BOND

-

COVALENT RADIUS DOUBLE BOND

-

COVALENT RADIUS TRIPLE BOND

110 pm

VAN DER WAALS RADIUS

1s¹

ELECTRON CONFIGURATION

Hexagonal, Primitive

CRYSTAL STRUCTURE

-

DENSITY AS SOLID

-

DENSITY AS LIQUID

0.089'88 g/cm³

DENSITY AS GAS

P6₃/mmc

SPACE GROUP NAME

194

SPACE GROUP NUMBER

π/2, π/2, 2π/3

LATTICE ANGLES

470, 470, 340 pm

LATTICE CONSTANTS

1

VALENCE

2.2

ELECTRONEGATIVITY

72.77 kJ/mol

ELECTRON AFFINITY

IONISATION ENERGY