Why is the symbol for Strontium Sr and not St?

Answer 1

There's no specific reason for Strontium having the atomic symbol Sr instead of St. The only ones who'd know why are the original discoverers of the element. Usually, for most chemical elements, the atomic symbol is the first letter, first two letters, or even the first and third letter of their names, like Strontium. Magnesium (Mg), Manganese (Mn), Zinc (Zn), and Arsenic (As), are some other examples of this like Strontium (Sr).