when solutions of silver perchlorate, a g c l o 4 ( a q ) , and ammonium iodide, n h 4 i ( a q ) , are mixed, a solid precipitate forms, indicating a reaction.

Sorry i dont understand the question can you rephase it?

There is no reason to think the results are biased or not conducted properly but you should not assume the results are correct just because they were done in a laboratory so the answer would be c. it is likely to be reliable because the results support the conclusion presented.

Ithink about 50 % of an original isotope's number of atoms remain

As long as you're breathing, you'll be fine : /p. s. if you aren't breathing, you'll pass out. mark as brainliest.