No. of elements in KMnO4​

3 three

Explanation:

potassium (K), manganese (Mn), and oxygen (O).

3 different elements (7 in total as there are 4 oxygens (The answer is either one of these))

Explanation:

so here we go

atomic mass

239 + 1 = y + 134 + 3 combine like terms

240 = y + 137             subtract 137 from both terms

240 - 137 = y

103 = y

atomic number

94 = z +54 + 0

94 = z + 54               subtract 54 from both sides.

40 = z

answer

i think its 100

i hope this !