It would have 20 protons, 20 neutrons, and 20 electrons. Protons and electrons are USUALLY (I say usually because of the different types of atoms) the same as the atomic number. To find neutrons you take the atomic mass minus the atomic number. 40-20=20
The answer is oil.
The United States' fossil shortage of oil makes the country dependent on outside sources. Mineral oil such as crude oil or commonly known as petroleum came from the ancient fossilized organic materials. This resource is limited. The US is now facing a shortage in oil and becoming dependent to some countries such as middle-east countries.
Found in eukaryotic cells
Prey or predation is a biological interaction where a predator (an organism, often an animal) kills and eats its prey (another organism).
Like a mouse getting caught and eaten by a bird of prey (Eagles, hawks, etc.)