Different symbols are used but if you are referring to the greek symbol "σ", it is pronounced "sigma" (like stigma without the t).
The three symbols of word stress are the primary stress symbol ( ˈ ), the secondary stress symbol ( ˌ ), and the unstressed symbol ( ˈ ). The primary stress symbol is used to mark the syllable that is stressed the most in a word, while the secondary stress symbol marks syllables that are stressed less than the primary stress but more than the unstressed syllables. The unstressed symbol is used for syllables that do not carry any stress.
symbol = סמל (SEM-el)
Born does not have a formula but a symbol as it is an element. its symbol is B.
Before a symbol. Not sure about a formula.
The chemical formula (not symbol) of sodium sulfide is Na2S.
The chemical symbol (not formula) of phosphorous is P; the chemical symbol (not formula) of chlorine is Cl.
The chemical symbol of indium is In.
Silver is a symbol (Ag)
The chemical formula of hydrobromic acis is HBr.
There is NO symbol for sodium phosphate. It is a chemical formula. The chemical formula is ' Na3PO4 '.
With the symbol of a chemical element - of course, if you think to a chemical formula.
Ag is silver's formula and symbol.