When two magnets are brought near each other, like poles repel; opposite poles attract. When a magnet is brought near a piece of iron, the iron also gets attracted to the magnet, and it acquires the same ability to attract other pieces of iron.
I believe it would be the second one. Because it is asking how to prevent it before it happens so it would not be a or d and c would not be good because you do not want to smell chemicals.
Answer:
3
Explanation:
remember the equation percentage yield = actual/ theoretical yield as
4.20/4.88 x 100
86.065 so 86.1.
hope this make sense:)