Alcium carbonate is a compound that is used to make chalk for drawing on rocks or pavement. one molecule has one atom of calcium (ca), one atom of carbon (c), and three atoms of oxygen (o). which is the correct way to write the chemical formula for calcium carbonate?

Two identical stars with mass m orbit around their center of mass. each orbit is circular and has radius r, so that the two stars are always on opposite sides of the circle. (a) find the gravitational force of one star on the other. (b) find the orbital speed of each star and the period of the orbit. (c) how much energy would be required to separate the two stars to infinity?