Question

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

Answer 1

To approach this question, we should know that every element of the periodic table is arranged in the order of increasing atomic number and has a unique symbol. This symbol represents one atom of that element and does not describe its properties..

Complete step by step answer:
Though the beginning alphabet used for elements like sodium, silicon and sulphur is the same, the symbol for these elements are different. Let us know the roots from where this emerged.
The symbols of elements are usually derived from the Latin or Greek synonyms. This is done to avoid the confusion with the English names. For example, the symbol for sodium is derived from the Latin word Natrium. That’s why we use the symbol $Na$ for sodium. Similarly, sulfur is a Latin word that means to burn and in English language, it is renamed as sulphur and thus the initial letter of the word is used as the symbol for sulfur.

Additional information:

Serial number	Name of the element	Symbol	Atomic number	One extraordinary property.	Metal/non-metal
1.	Sodium	$Na$	11	Catches fire when kept in open.	Metal
2.	Silicon	$Si$	14	Tetravalent atom that is widely used in semiconductors.	Non-metal
3.	sulfur	$S$	16	Crystalline solid	Non-metal

Note:
As we discussed for $Na$ and $S$ , similarly $Si$ got the symbol from its Latin word silicis or silex which means flint or hard stone. This element of amorphous nature is widely used in ferrosilicon for steel making.