You could ask whether the black crust is a new substance formed from silver underwent a chemical change because a chemical change produces a new substance.
Answer:
It's A
Explanation:
Animals get the nitrogen they need by eating plants or other animals that contain nitrogen. When organisms die, their bodies decompose bringing the nitrogen into soil on land or into ocean water. Bacteria alter the nitrogen into a form that plants are able to use.
Answer:
Minera and Aragonite
Explanation:
Limestone is a common type of carbonate sedimentary rock. It is composed mostly of the minerals calcite and aragonite, which are different crystal forms of calcium carbonate (CaCO 3). Limestone forms when these minerals precipitate out of water containing dissolved calcium.
Answer:
2n^2 electrons
Explanation:
for example, the first level contain 2*(1^2) = 2 electrons, the second level contain 2*(2^2) = 8 electrons, etc
