My question came from looking at this one Why is "math" always pluralized in British English and singular in American English?. Why are words like Mathematics and Physics pluralised? On a side note i just noticied that i used an 's' instead of a 'z' in pluralised. Why do some countries use 's' and others 'z' in some words?
The OED generally prefers the 'z' over the 's' forms of words in modern English usage. The 's' forms often relate to archaic Norman roots of words; and today, the 's' forms are normally found in areas where both French and English still mix (for example, in Canadian English).