Question

Why is the symbol S for sulphur, but Na for sodium and Si for silicon ?​

Answer 1

Answer:

because symbol s was already taken for sulphur si is the symbol for silicon.

Answer 2

Not all elements symbols are the first letters (or first two letters) of their english names, like 'S' for Sulphur.

Others' symbols are the first letters of their Latin/Greek names, and other objects.

"Natrium" is the Latin name of sulphur, which is where sulphur got its symbol from - "Na".

Silicon's symbol is derived from the Latin "silex" or "silicis", meaning "flint" or "hard stone" - "Si".

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