uranium-235

Also known as U-235, 235U, ²³⁵U

Uranium-235 (' or U-235') is an isotope of uranium making up about 0.72% of natural uranium. Unlike the predominant isotope uranium-238, it is fissile, i.e., it can sustain a nuclear chain reaction. It is the only fissile isotope that exists in nature as a primordial nuclide and was discovered in 1935 by Arthur Jeffrey Dempster.

Key facts

Isotope.image: HEUraniumC.jpg
Isotope.image_caption: Uranium metal highly enriched in uranium-235
Isotope.mass_number: 235
Isotope.symbol: U
Isotope.num_neutrons: 143
Isotope.num_protons: 92
Isotope.abundance: 0.72%
Isotope.decay_product: Thorium-231
Isotope.decay_mass: 231
Isotope.decay_symbol: Th
Isotope.parent: Protactinium-235
Isotope.parent_mass: 235
Isotope.parent_symbol: Pa
Isotope.parent_decay: b-
Isotope.parent2: Neptunium-235
Isotope.parent2_mass: 235
Isotope.parent2_symbol: Np
Isotope.parent2_decay: b+

via Wikipedia infobox

Chemical data

Formula: U
Molecular weight: 235.04393 g/mol
IUPAC name: uranium-235
SMILES: [235U]
InChIKey: JFALSRSLKYAFGM-OIOBTWANSA-N
Polar surface area: 0 Å²
H-bond donors: 0
H-bond acceptors: 0
Formal charge: 0

via PubChem

Wikidata facts

Mass: 235.04392819
Image: HEUraniumC.jpg

Show 12 more facts

atomic number: 92
neutron number: 143
half-life: 704000000
natural abundance: 0.007204
spin quantum number: 3.5000
parity quantum number: -1
canonical SMILES: [U]
isomeric SMILES: [235U]
chemical formula: U
mass excess: 40918.846
binding energy: 1783864.79
Commons category: Uranium-235

Sources (6)

via Wikidata · CC0

~9 min read

Article

6 sections

Contents

Fission properties
Nuclear weapons
Decay
Astrophysical dating
References
External links

The release of energy from the fission of Uranium-235 powers most nuclear reactors and nuclear weapons. Uranium enrichment is the process of taking natural uranium and increasing the proportion of uranium-235. Some reactor types can use natural uranium directly, while nuclear weapons and some others reactor types require uranium enriched in U-235.