I believe the answer is "After adding two substances together a new order is detected" because nearly all of the other answers suggest a chemical change has taken place. The reason I say "almost" is because answer two and four results in bubbles forming so the answer cannot be both. The only one to not clearly show a chemical change has occurred is the last answer.
Answer: 94.07%
Explanation:
Percentage yield can be calculated by the formula
%yield = Experimental yield/Theoretical yield x100
Experimental yield = 7.93g
Theoretical yield = 8.43
%yield = Experimental yield/Theoretical yield x100
%yield = 7.93/8.43 x 100 = 94.07%
