The belief of early astronomers that the Earth was the center of the universe is called the theory. A. equatorial

B. heliocentric

C. solar centric

D. geocentric

the relative atomic mass of an element is the mass of one atom of that element, relative to 1/12th of the mass of a  1212c atom. to convert to an absolute mass in kg, it is necessary to multiply by  1.661×10−271.661×10−27.

the relative atomic mass is roughly equal to the number of neutrons, plus the number of protons, in the nucleus of the atom.

for elements with more than one stable isotope (different types of nucleus with different numbers of neutrons but the same number of protons), the quoted mass is usually the average mass, weighted by the relative abundance of the different isotopes.

phosphorus cycle

explanation:

the phosphorus cycle is the way that compounds of the element phosphorus, an essential nutrient, are recycled in the environment. plants absorb phosphorus compounds from the soil, and decaying organic matter, including both plant matter and animal droppings, returns it to the soil. phosphorus is a vital part of atp, the energy currency of all cells, and is vital to all forms of life.