mercury can be obtained by reacting mercury(II) sulfide with calcium oxide. How many grams of calcium oxide are needed to produce 33.1 g of Hg?

Matter- occupies space and possesses rest massno matter is the opposite

C) electrons encircling a nucleus with neutrons and protons

The density of water is 1 g/cm cubed and in order for the pebble to sink its density has to be greater than the density of water and in order for the twig to float its density has to be less than the density of water

Your question is not clear but if you can explain yourself i would be glad to .  just trying to : ))