Definition

1. Noun:
   • A chemical compound containing two atoms of oxygen per molecule: Dioxide is a type of oxide (a compound of oxygen with another element) where exactly two atoms of oxygen are bonded to another atom or group of atoms in its molecular formula.

Usage

• The term "dioxide" is used in chemistry to name specific compounds. It is typically preceded by the name of the other element(s) it is combined with.
• It is a countable noun. You can have dioxide or multiple .

Examples

• Noun:
  • Carbon dioxide is a greenhouse gas.
  • Silicon dioxide is the main component of sand.
  • The car's emissions include nitrogen dioxides.

Advanced Usage

• In chemical nomenclature: The prefix "di-" indicates two oxygen atoms. For example, CO₂ is carbon dioxide (one carbon atom, two oxygen atoms). TiO₂ is titanium dioxide.
• Environmental and industrial contexts: Specific dioxides are frequently discussed in topics like climate change (carbon dioxide), pollution (sulfur dioxide, nitrogen dioxide), and manufacturing (titanium dioxide as a pigment).

Variants and Related Words

• Monoxide (n): An oxide containing one atom of oxygen in the molecule (e.g., carbon monoxide, CO).
• Trioxide (n): An oxide containing three atoms of oxygen in the molecule (e.g., sulfur trioxide, SO₃).
• Peroxide (n): A compound containing an oxygen-oxygen single bond, often seen as a variant oxide (e.g., hydrogen peroxide, H₂O₂).

Synonyms

• Compound: A more general term for a substance formed from two or more elements chemically united in fixed proportions.
• Oxide: The broader category of chemical compounds of oxygen with another element.

Related Phrases

• Carbon dioxide emissions: Gases released from burning fossil fuels.
• Titanium dioxide sunscreen: A type of physical sunblock using the compound TiO₂.

Notes

• The word "dioxide" itself is not typically used in idioms or phrasal verbs. Its usage is almost exclusively technical and scientific.
• Do not confuse with similar-sounding words like "dioxin," which is a different class of toxic chemical compounds.

Noun

1. an oxide containing two atoms of oxygen in the molecule