Sandy soil because the sand will erode faster then the clay will causeing the well to cave in
Question one should be obvious..
Mass can't be created not destroyed no matter what, so even in a chemical reaction, the answer will remain. The first answer is correct.
Question two
No, because even when water is broken down, there should only be one molecule of oxygen. The fact there is two means it's incorrect.
Question three
Yes. The equation is perfectly balanced on both sides, so it's safe to say the value of mass remains constant.
1. Pipette, measuring cylinder
The most brittle one is selenium!
