Hydrogen

Hydrogen is a chemical element with the symbol H and atomic number 1. It is a colorless, odorless, tasteless, non-toxic, highly flammable gas, the lightest of all gases. Hydrogen is the most abundant chemical substance in the universe, constituting roughly 75% of all baryonic mass. Stars in the main sequence are mainly composed of hydrogen in its plasma state. It is also a component of water and most organic compounds.

Overview

English Name:

Hydrogen

Latin Name:

Hydrogenium

Year Discovered:

1766

Discovered By:

Henry Cavendish

Group:

1

Period:

1

Electrons:

1

CAS Number:

1333-74-0

Cost Per 100 Grams:

$0.01

Atomic Properties

Electronic Configuration:

1s¹

Ion Charge:

+1

Ionisation Energies:

1312.0 kJ/mol

Atomic Radius (Empirical):

25 pm

Atomic Radius (Calculated):

53 pm

Covalent Radius:

31 pm

Van Der Waals Radius:

120 pm

Ionisation Potential of An Atom:

13.59844 eV

Electrons Per Layer:

1

Atomic Multiplicities Of The Gas:

1

Atomic Weight:

1.008

Oxidation States

-1
+1

Reactivity

Electron Affinity:

72.8 kJ/mol

Valence:

1

Electronegativity:

2.20

Thermal Properties

Melting Point:

-259.14°C

Boiling Point:

-252.87°C

Critical Point:

Pressure: 1.296 MPa

Temperature: -239.95°C

Thermal Conductivity:

0.1805 W/(m·K)

Heat Capacity:

Specific: 14.304 J/(g·K)

Molar: 28.836 J/(mol·K)

Thermal Coefficient:

0.00366

Enthalpy:

Fusion: 0.117 kJ/mol

Vaporisation: 0.904 kJ/mol

Atomization: 217.998 kJ/mol

Curie Temperature:

N/A

Neel Temperature:

N/A

Superconductivity Point:

N/A

Physical and Chemical Properties

State of matter (25° C/ 77°F):

Gas

Density:

Gas: 0.0899 g/L

Molar Volume (Vmol):

22.4 L/mol

Speed of Sound (Vs):

1310 m/s

Hardness:

N/A

Bulk Modulus (K):

1.02 GPa

Shear Modulus (G):

N/A

Young's Modulus (E):

N/A

Color:

Colorless

Brinell Hardness (MPa):

N/A

Liquid Density (Kg/m^3):

70.8 kg/m³

Hardness of Mohs:

N/A

Refractive Index:

1.000132

Vickers Hardness (MPa):

N/A

Crystal Structure:

N/A

Electromagnetic Properties

Electrical Type:

Insulator

Resistivity:

1.08 × 10¹⁶ Ω·m

Magnetic Type:

Diamagnetic

Superconductivity:

Not applicable

Volume Magnetic Susceptibility:

-2.193 × 10^-9

Mass Magnetic Susceptibility:

-2.438 × 10^-9 m³/kg

Molar Mass Susceptibility:

-2.456 × 10^-9 m³/mol

Electrical Conductivity:

9.2 × 10^-15 S/m

Mass (γmass):

1.6735 × 10-27 kg

Mass (γmol):

1.6735 × 10-24 mol

Volume (γvol):

22.4 L

Grid Parameters

Crystal Structure:

N/A

Grid Parameters:

N/A

Attitude:

N/A

Debye Temperature:

N/A

Safety and Precautions

Signal Word:

Danger

Hazard Statements:

H220, H280

Precautionary Statements:

P210, P377, P381, P403

RTECS Number:

MW8900000

Risk:

Flammability: Extremely flammable
Health Risk: Asphyxiant
Reactivity: Stable
Specific Risk: Embrittles steel

Importance

Main sources:

Natural gas, water, coal

Main Usage:

Fuel, industrial processes, rocket propellant, welding

Nuclear Properties

Radioactive:

No

Isotopes:

H-1, H-2, H-3

Neutron Cross Sectional:

0.332 barns

Half Life (s):

None

Lifetime:

Stable

Prevalence

Universe:

75%

Sun:

92%

Oceans:

11%

Humans:

0.5%

Earth's Crust:

0.14%

Meteorites:

0.18%