(i) Correct symbol for sodium is Na. The symbol of sodium was derived from its latin name “natrium”.

(ii) Correct name for hydrogen is “H”. The symbol “Hg” is used for mercury.

(iii) Correct symbol for copper is Cu. The symbol “Co” is used for cobalt.

(iv) The given symbol of sulphur (S) is correct.

(v) Correct symbol for calcium is “Ca”. According to IUPAC, the first letter of the symbol is always written as a capital letter (uppercase) and the second letter is always written as a small letter (lowercase). Both letters cannot be written as capital letters.