ABOUT HYDROGEN

HYDROGEN

Symbol --- H

Abundance --- Most abundant element in the universe (75%), in earth (0.9%).

Physical state --- gas

Elemental Category --- nonmetal

Colour --- colourless

Discovery --- Henry Cavendish (1766)

Atomic no --- 1

Atomic weight --- 1.007

Period --- 1

Group --- 1

Block --- s-block

Known Isotopes--- ₁H¹ ₁H² ₁H³ ₁H⁴ ₁H⁵ ₁H⁶ ₁H⁷

Stable Isotopes --- ₁H¹ ₁H² 

Radioactive Isotope --- ₁H³

Isotopic abundance--------- [₁H¹(99.98%),₁H²(0.115%),₁H³(trace)]

Melting Point --- 13.99 K or -259.16 ⁰C

Boiling Point --- 20.27 K or -252.88 ⁰C

Density (at STP) --- 0.0898 g/L

Electron Configuration --- 1s¹

Oxidation States --- +1, -1

Valence --- 1

Electronegativity --- 2.2

Electron Affinity --- 72.8 KJ/mol

Ionisation Energy --- 1312 KJ/mol

Covalent Radius --- 31 pm

Van der Waals radius --- 120 pm

Crystal Structure --- Hexagonal

Heat of fusion --- 0.117 KJ/mol

Heat of vaporisation --- 0.904 KJ/mol

Triple Point --- 13.8 K, 7.04 KPa

Critical Point --- 32.92 K, 1.28 MPa (12.76 atm)

Molar heat capacity --- 28.83 J/mol-K

Specific heat --- 14300 J/(Kg-K)

Thermal conductivity --- 0.1805 W/(m k)

Adiabatic index --- 7/5

Molar volume --- 0.0112

Refractive index --- 1.000132

Speed of sound --- 1310 m/s

Magnetic type --- diamagnetic

Mass magnetic susceptibility ---  - 2.48x10^-8 m³/kg

Molar magnetic susceptibility --- 

- 4.999x10^-11 m³/mol 

Lattice angles --- π/2, π/2, 2π/3

Lattice constants --- 470 pm,470 pm,340 pm

Quantum numbers --- ²S_1/2

Neutron cross section --- 0.332

Neutron mass absorption --- 0.011

ABOUT HYDROGEN