Definition

1. Noun:
   • A chemical element: "atomic number 7" is the scientific designation for the chemical element nitrogen (symbol N). It is a common, nonmetallic element that is normally a colorless, odorless, tasteless, and inert diatomic gas (N₂) under standard conditions.
   • A major atmospheric component: It constitutes approximately 78 percent of the Earth's atmosphere by volume.
   • A biological constituent: It is a fundamental constituent of all living tissues, found in molecules like amino acids, proteins, and nucleic acids (DNA/RNA).

Usage Examples

• Noun:
  • The periodic table lists the element with atomic number 7 as nitrogen.
  • Atomic number 7 is crucial for the formation of proteins in organisms.
  • Although atomic number 7 is abundant in the air, most organisms cannot use it directly from the atmosphere.

Advanced Usage

• Scientific and Technical Contexts: The term "atomic number 7" is primarily used in formal scientific, educational, or technical writing to specify the element precisely by its fundamental property (the number of protons in its nucleus).
  • The fertilizer is enriched with compounds containing atomic number 7 to promote plant growth.

Variants and Related Words

• Nitrogen (N): The common name for the element designated by atomic number 7.
  • Liquid nitrogen is used as a cryogenic fluid.
• Dinitrogen (N₂): The term for the molecule composed of two nitrogen atoms, which is the common gaseous form.
  • Dinitrogen is the most abundant gas in our atmosphere.

Synonyms

• Nitrogen: The standard and synonymous name for this element.
• N (symbol): The chemical symbol for the element.

Related Phrases / Compounds

• Nitrogen fixation: The chemical process by which atmospheric nitrogen (N₂) is converted into ammonia or related nitrogenous compounds, typically by bacteria.
  • Legumes host bacteria that perform nitrogen fixation.
• Nitrogen cycle: The biogeochemical cycle by which nitrogen is converted into various chemical forms as it circulates among the atmosphere, terrestrial, and marine ecosystems.
  • Understanding the nitrogen cycle is essential for ecology.

Noun

1. a common nonmetallic element that is normally a colorless odorless tasteless inert diatomic gas; constitutes 78 percent of the atmosphere by volume; a constituent of all living tissues