Question

?? ==> 15/7 N + 0/-1 e
What is the reactant for this equation?
15/6 C
16/5 B
14/6 C
14/5 B

Answer 1

Make the superscripts and the subscripts add to the same number on both sides of the equation. For example, the top numbers would look like this.
?? ==> 15/7 N + 0/-1 e
15X ==> 15/7 N + 0/-1 e and you know that number is 15 because on the right you hve 15 + 0 = 15.
Now for the lower number on that 15X, you put that in
15/?X ==> 15/7N + 0/-1 e When you know the lower number, that is the atomic number so look on the periodic tble and see what that element X is and write in the symbol.