Answer:
A river forms from water moving from a higher elevation to a lower elevation, all due to gravity. ... As small creeks flow downhill they merge to form larger streams and rivers. Rivers eventually end up flowing into the oceans. If water flows to a place that is surrounded by higher land on all sides, a lake will form.
Answer:
finding the mass percentage oven element in a compound might sound complicated, but the calculation is simple. For example, to determine the mass percentage of hydrogen in water H2O, divide the major mass of hydrogen by the total molar mass of water and then multiply the result by 100