becquerel

physics

Also known as: Bq

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June 17, 2026

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The term "becquerel" can refer to two related concepts in physics: the unit of radioactivity and the physicist who discovered it.

Henri Becquerel (1852–1908) was a French physicist who discovered radioactivity in 1896. While investigating uranium compounds, he observed that they emitted penetrating radiation similar to X-rays, even without exposure to sunlight. This groundbreaking discovery earned him a share of the Nobel Prize in Physics in 1903, alongside Pierre and Marie Curie.1

The becquerel (Bq) is the SI unit of radioactivity, defined as one atomic decay per second. It is used to measure the rate at which a radioactive material decays.2

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activity
…System of Units by the becquerel (abbreviated Bq), which is exactly equal to one disintegration per second. One becquerel is a very small amount of radioactivity. For example, household smoke detectors typically contain 0.3 micrograms of the radioactive isotope americium-241, which emits about 37,000 Bq. The old standard unit was…
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…System of Units by the becquerel (abbreviated Bq), which is exactly equal to one disintegration per second. One becquerel is a very small amount of radioactivity. For example, household smoke detectors typically contain 0.3 micrograms of the radioactive isotope americium-241, which emits about 37,000 Bq. The old standard unit was…
Read More

radiation
Units for measuring ionizing radiation
…sample of matter are the becquerel (Bq) and the curie (Ci). One becquerel is that quantity of a radioactive element in which there is one atomic disintegration per second; one curie is that quantity in which there are 3.7 × 10¹⁰ atomic disintegrations per second (1 Bq = 2.7 ×…
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…sample of matter are the becquerel (Bq) and the curie (Ci). One becquerel is that quantity of a radioactive element in which there is one atomic disintegration per second; one curie is that quantity in which there are 3.7 × 10¹⁰ atomic disintegrations per second (1 Bq = 2.7 ×…
Read More