Kappa

Kappa (uppercase/lowercase Κ κ) is the letter of the Greek alphabet used to represent the "k" sound in Ancient and Modern Greek. In the system of Greek numerals, it has a value of 20. Letters that came from it include the Roman K and Cyrillic К.

The letter κ always stands for the sound "k" in Greek. It is customary to transliterate (re-write) κ as "c" in English, but this is somewhat problematic since c is pronounced as "s" before e, i and y (which does not happen in Greek).

In mathematics, the lowercase  is used to represent the curvature of a curve, while the uppercase Κ is used to represent an ordinal number which is also a cardinal number.

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 Thermal conductivity, represented by 

 References 

Category:Greek alphabet