Answer:
Incomplete precipitation of barium sulfate
Explanation:
The student has precipitated and digested the barium sulfate on his/her side. But on the addition of
in the solution, the solution become cloudy. This happened because incomplete precipitation of barium sulfate by the student. When
is added, there are still sulfate ions present in the solution with combines with
and forms
and the formation of this precipitate makes the solution cloudy.
Breaking an egg is an example of a physical change. This is because the egg was broken, thus its physical appearance was different. If you were to cook the egg, that would be a chemical change because that would result in a new chemical formation of the stuff inside of the egg. But since you're only breaking the egg, it's just a physical change.
I guess that answers both questions.
Hope that helped!
Mg0 + NacI, hope it helps ffammmm!!!!