Curie

The curie (symbol Ci) is a non-SI unit of radioactivity, named 'in honour of' Pierre Curie, according to his widow, the famed radiation researcher Marie Curie, who was on the standards committee and perhaps a more likely candidate for the naming honors.

It was originally defined as "the quantity or mass of radium emanation in equilibrium with one gram of radium (element)" but is currently defined as: 1 Ci = 3.7 × 10¹⁰decays per second after more accurate measurements of the activity of ²²⁶Ra (which has a specific activity of 3.66 x 10¹⁰ Bq/g.)

In 1975 the General Conference on Weights and Measures gave the becquerel (Bq), equal to one reciprocal second, official status as the SI unit of activity. Therefore:

and

While its continued use is discouraged by NIST and other bodies, the curie is still widely used throughout the government, industry and medicine in the United States and in other countries.

The curie is a large amount of activity, and was intentionally so. According to Bertram Boltwood, Marie Curie thought that 'the use of the name "curie" for so infinitesimally small (a) quantity of anything was altogether inappropriate.'

Écurie

Écurie is a commune in the Pas-de-Calais department in the Nord-Pas-de-Calais region of France.

Geography

A farming village situated 3 miles (4.8 km) north of Arras at the junction of the N17 and D60 roads.

Population

Places of interest

See also

References

External links

Curie (Martian crater)

Curie Crater is an impact crater in the Oxia Palus quadrangle of Mars, located at 29.1° N and 4.8° W. It is 114.1 km in diameter and was named after Pierre Curie, a French physicist-chemist (1859-1906).

Impact craters generally have a rim with ejecta around them, in contrast volcanic craters usually do not have a rim or ejecta deposits. As craters get larger (greater than 10 km in diameter) they usually have a central peak. The peak is caused by a rebound of the crater floor following the impact.

Curie Crater, as seen by CTX camera (on Mars Reconnaissance Orbiter).

Curie Crater, as seen by CTX camera (on Mars Reconnaissance Orbiter).

Channels in Curie Crater, as seen by CTX camera (on Mars Reconnaissance Orbiter). Note: this is an enlargement of the previous image.

Channels in Curie Crater, as seen by CTX camera (on Mars Reconnaissance Orbiter). Note: this is an enlargement of the previous image.

Close-up of layers in central mound of Curie Crater, as seen by HiRISE.