Symbol: H

Atomic Number: 1

Atomic Mass: 1.008 u

Group: 1 (Alkali Metals)

Period: 1

Block: sblock

State: Gas at room temperature

Color: Colorless

Odor: Odorless

Density: 0.08988 kg/m³ (at 0°C)

Melting Point: 259.2°C (434.5°F)

Boiling Point: 252.8°C (423.1°F)

Reactivity: Highly reactive with oxygen

Combustion: Burns in air to form water

Isotopes: Three isotopes (protium, deuterium, tritium)

Electrolysis of water

Steam reforming of natural gas

Coal gasification

Biological production

Fuel (rocket fuel, fuel cells)

Industrial processes (ammonia production, oil refining)

Medical applications (MRI contrast agent)

Research (fusion energy)

Greenhouse gas reduction potential

Renewable energy source

Hydrogen economy prospects

Flammability (explosive mixtures with air)

Storage and transportation challenges

Hydrogen embrittlement of metals

First element in the periodic table

Discovery attributed to Henry Cavendish in 1766

Named after the Greek words for "waterformer"

Protium (most abundant, no neutrons)

Deuterium (one neutron, used in nuclear reactors)

Tritium (two neutrons, radioactive, used in luminous paints)

Abundance: Most abundant element in the universe

Stars: Principal component of stars

Formation: Primordial element from Big Bang nucleosynthesis