Definition

Noun: - A fissile isotope of uranium with an atomic mass of 235, used as the primary fuel in nuclear reactors and nuclear weapons due to its ability to sustain a nuclear chain reaction.

Usage

• As a subject: "Uranium 235 is less abundant than uranium 238."
• As an object: "The reactor core is enriched with uranium 235."
• With prepositions: "The fission of uranium 235 releases a significant amount of energy."

Examples

• Scientific Context:
  • Uranium 235 must be enriched from natural uranium for most nuclear applications.
  • When a neutron strikes a uranium 235 nucleus, it can cause fission.
• Industrial/Energy Context:
  • The power plant uses fuel rods containing enriched uranium 235.
  • The treaty limits the enrichment level of uranium 235 for civilian use.

Advanced Usage

• "Weapons-grade uranium 235": Refers to uranium 235 that has been highly enriched (typically above 90%) for use in nuclear weapons.
  • The non-proliferation agreement aims to prevent the accumulation of weapons-grade uranium 235.
• "Fissile uranium 235": Emphasizes its property of undergoing fission with low-energy neutrons.
  • Plutonium-239 and uranium 235 are the main fissile materials.

Variants and Related Words

• U-235: A common shorthand notation for uranium 235.
  • The sample was tested for its U-235 concentration.
• Enriched uranium: Uranium that has had its proportion of U-235 increased.
  • Low-enriched uranium contains only a few percent uranium 235.
• Depleted uranium: Uranium from which most of the uranium 235 has been removed.
  • Depleted uranium is a byproduct of the uranium 235 enrichment process.

Synonyms

• Fissile isotope of uranium: A descriptive synonym highlighting its key property.
• U-235: The abbreviated form.

Related Phrases

• "Sustain a chain reaction": This phrase is intrinsically linked to the definition of uranium 235.
  • The critical mass is the minimum amount of uranium 235 needed to sustain a chain reaction.
• "Undergo fission": Describes the primary nuclear process for uranium 235.
  • The probability that uranium 235 will undergo fission when it captures a neutron is very high.

Noun

1. a uranium isotope with mass number 235; capable of sustaining chain reactions