1 H 1.008

Hydrogen

diatomic nonmetal

Properties

Atomic number
1
Atomic mass
1.008 u
Category
diatomic nonmetal
Group
1
Period
1
Block
s-block
State (room temp)
Gas
Outer-shell electrons
1
Electronegativity
2.2 (Pauling)
Density
-
Melting point
-259.16 °C
Boiling point
-252.88 °C

Electron configuration

1s¹

Noble-gas shorthand: 1s¹

Electrons per shell: 1, which is 1 in the outermost shell.

Related: electron configuration, the Bohr model, valence electrons.

H
Bohr model; outer-shell electrons in blue

About Hydrogen

Hydrogen is a chemical element with chemical symbol H and atomic number 1. With an atomic weight of 1.00794 u, hydrogen is the lightest element on the periodic table. Its monatomic form (H) is the most abundant chemical substance in the Universe, constituting roughly 75% of all baryonic mass.

Hydrogen: frequently asked questions

What is Hydrogen?
Hydrogen (H) is the chemical element with atomic number 1. It is a nonmetal (diatomic nonmetal).
What is the atomic number of Hydrogen?
Hydrogen's atomic number is 1, which means every Hydrogen atom has 1 protons in its nucleus.
What is the electron configuration of Hydrogen?
The electron configuration of Hydrogen is 1s1 (noble-gas shorthand: 1s1). Its electrons are arranged in shells of 1, with 1 in the outermost shell.
Is Hydrogen a metal or a nonmetal?
Hydrogen is a nonmetal (diatomic nonmetal).
What group and period is Hydrogen in?
Hydrogen is in group 1 and period 1 of the periodic table.
Is Hydrogen a solid, liquid, or gas?
At room temperature, Hydrogen is a gas.

Position in the periodic table

Open the interactive periodic table →

Data compiled from Wikipedia, PubChem, and IUPAC. Source.