Hydrogen (H) — Reactive nonmetal. Atomic number 1.
Colorless, odorless gas
- Atomic number: 1
- Symbol: H
- Atomic mass: 1.008 u
- Category: Reactive nonmetal
- State: Gas
- Melting point: -259.16 °C / 13.99 K
- Boiling point: -252.88 °C / 20.271 K
- Density: 8.20e-5 g/cm³ (20°C)
- Electron configuration: 1s1
- Oxidation states: −1, +1
- Electronegativity: 2.2
- Discovered by: Henry Cavendish (1766)
Common uses: Ammonia production, Fuel cells, Petroleum refining
Biological role: Essential component of water and organic molecules.
Frequently Asked Questions about Hydrogen
What is the atomic number of hydrogen?
Hydrogen has an atomic number of 1, meaning each atom contains 1 proton in its nucleus.
What is the atomic mass of hydrogen?
The standard atomic weight of hydrogen is 1.008 u (unified atomic mass units).
What category does hydrogen belong to?
Hydrogen is classified as a reactive nonmetal.
What is the state of hydrogen at room temperature?
Hydrogen is a gas at 20 °C (68 °F).
What is the melting point of hydrogen?
The melting point of hydrogen is -259.16 °C / 13.99 K.
What is the boiling point of hydrogen?
The boiling point of hydrogen is -252.88 °C / 20.271 K.
What is the density of hydrogen?
The density of hydrogen is 8.20e-5 g/cm³ (20°C).
What is the electronegativity of hydrogen?
Hydrogen has a Pauling electronegativity of 2.2.
What is the electron configuration of hydrogen?
The electron configuration of hydrogen is 1s1.
What are the common oxidation states of hydrogen?
Hydrogen commonly exhibits the following oxidation states: −1, +1.
When was hydrogen discovered?
Hydrogen was discovered in 1766 by Henry Cavendish.
Is hydrogen radioactive?
Hydrogen is a stable element with no naturally occurring radioactive isotopes.
What is the biological role of hydrogen?
Essential component of water and organic molecules.
What are the common uses of hydrogen?
Hydrogen is used for: Ammonia production; Fuel cells; Petroleum refining.
