Definition

Noun: A unit of radioactivity equal to one thousandth (1/1000) of a curie. It is a measurement of the rate at which a quantity of radioactive material decays or disintegrates.

Usage

The term "millicurie" is a specific scientific unit used in nuclear physics, medicine (particularly in radiation therapy and diagnostic imaging), and environmental science to quantify radioactivity. It is a metric subunit of the curie, which is a non-SI unit.

Examples

• The laboratory handled a sample with an activity of five millicuries of iodine-131.
• The safety protocol requires shielding for any source exceeding one millicurie.
• The diagnostic tracer had a very low radioactivity, measured in tenths of a millicurie.

Advanced Usage

• The millicurie (mCi) is commonly used in the United States in medical and industrial contexts, though the International System of Units (SI) unit, the becquerel (Bq), is the global standard. One millicurie equals 37 megabecquerels (37 MBq).
• It is typically used with a numerical value and the symbol "mCi" (e.g., 2.5 mCi).

Variants and Related Words

• Curie (Ci): The base unit, equal to 37 billion disintegrations per second.
• Microcurie (µCi): A unit equal to one millionth of a curie.
• Becquerel (Bq): The SI unit of radioactivity, equal to one disintegration per second.
• Radioactivity: The property of certain nuclei to spontaneously emit particles or radiation.

Synonyms

• mCi (the standard abbreviation).
• (There are no true conceptual synonyms, only equivalent values in other units like megabecquerel).

Related Phrases

• Millicurie-hour: A unit of radiation exposure or dose, representing the product of activity (in millicuries) and time (in hours).
• Millicurie therapy: A historical term for radiation treatment using sources quantified in millicuries.

Noun

1. a unit of radioactivity equal to one thousandth of a curie