1
H
Nonmetal

Hydrogen

Atomic number 1 · Period 1 · Block S

H · Hydrogen
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Understanding the element

Hydrogen (H) is chemical element 1. It belongs to the nonmetals, and its reference state at room temperature is a gas. Those basic facts are a useful starting point for its chemistry and applications.

Where do we encounter it?

In practice, it turns up most often in water and the chemistry of life, fertiliser production and oil refining.

water and the chemistry of lifefertiliser productionoil refining
Standard atomic weight[1.00784, 1.00811]

What its position in the table tells us

Hydrogen sits in period 1, group 1 and the S block. That location is useful because neighbouring elements often share trends in valence electrons, oxidation states and bonding behaviour.

Worth remembering
Hydrogen has a characteristic place in the periodic table that helps explain both its chemistry and its practical uses

Scientific sources

Element identity
Atomic number1
Group1
Period1
BlockS
CategoryNonmetal
PhaseGas