What does the 2 mean in the formula 5Mg3(PO4)2

Match term definition ellipse a) diagonal cross section of a cylinder circle b) diagonal cross section through the widest part of a sphere sphere c) cross section parallel to the base of a cone great circle d) shape created when a semi-circle is rotated around the y-axis triangle e) perpendicular cross section of a cone

‘which reaction would most likely require the use of an inert electrode?

What are the two largest greenhouse gases