Please help Chemical Changes?

Question

ok so I have to find a " mystery word " by filling in certain letters by answering questions as you will see...I've already gotten the word (it is equation) , but Im having trouble with naming the 3 questions


1st Problem - The arrow in a chemical equation means "yields" or "__."
(7th letter) *Which is E

3rd problem - Combination of chemical symbols used to represent a compound
(5th letter) *Which is U

7th question - Used to the right of formulas to tell the solution class
(5th letter) *Which is O

Answer 1

I'll do two of them for you:

3. formula

7. symbol