sodium

sodium — noun

1. Sodium is a basic chemical substance — element number 11 on the periodic table.

1.nounB1
Definition

Sodium is a basic chemical substance — element number 11 on the periodic table. It is a soft metal with a silvery-white colour that never occurs alone in nature; it always bonds with other elements, most often with chlorine to make table salt. The human body needs sodium to send nerve signals and for muscles to work properly.

Example

The doctor told Quan to reduce his sodium intake after his blood pressure went up.

sodium intake — medical/dietary collocation

A small piece of sodium metal reacts violently as soon as it touches water.

sodium metal reacts with water — safety warning in chemistry

Common collocations
  • sodium intake
  • sodium content
  • sodium levels
  • low-sodium diet
  • high-sodium foods
  • sodium chloride

Grammar Patterns

sodium + noun (sodium intake, sodium content, sodium levels)

low-/high- + sodium (low-sodium diet, high-sodium food)

Usage Note

Sodium is an uncountable noun — it never takes a plural form. In food and health writing it most often appears as a modifier: 'sodium intake', 'sodium content', 'low-sodium diet', 'high-sodium foods'. Note that 'salt' (sodium chloride) is a compound that contains sodium, but the two terms are not interchangeable in chemistry contexts.

Common Mistakes

This soup contains too many sodium.
This soup contains too much sodium.
Sodium is an uncountable noun; use 'much' instead of 'many'.
Sodium and salt are the same thing.
Sodium is a chemical element, while table salt is a compound made of sodium and chlorine.
Learners often confuse the element with the compound (sodium chloride).

Synonym discussion

Sense: noun/1

Sodium is the chemical element (symbol Na), a silver-white metal that never occurs alone in nature. Salt (also called table salt or sodium chloride) is the compound NaCl formed when sodium bonds with chlorine. In everyday cooking and food labelling, 'salt' and 'sodium' are often used loosely as if they mean the same thing — a food label might say 'low sodium' when what was reduced was table salt. In science, health, and nutrition, the distinction matters: your body needs sodium (the element) to transmit nerve signals, but it gets that sodium from salt. A 'low-sodium diet' means limiting salt intake, not the element itself.

sodium ↗salt ↗sodium chloride

Common collocations

Nouns

Phrases

  • low-sodium
  • high-sodium
  • sodium-free

Etymology

EnglishLatinArabic

The English name 'sodium' was coined in 1807 by the British chemist Sir Humphry Davy, who first isolated the metal by electrolysis. He based the name on 'soda' (the substance from which he extracted it) plus the '-ium' suffix used for metallic elements. The chemical symbol Na comes from the Latin word 'natrium', a term for a type of sodium carbonate used since ancient times.