According to the current theory, the earth's moon was formed a. together with earth c. from a portion of earth b. separately from earth d. from a leftover star

c. from a portion of Earth

Explanation:

There are various theories suggesting the formation of Moon. The most accepted theory is the Giant Impact hypothesis. It is the one that suggests that the moon was formed from a portion of the Earth when a Mars sized object collided with the it and the leftover debris clumped together due to gravity to form the moon.

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.

not only is it colder, it also becomes darker, less salty, and more dense.