What is the second most abundant isotope of oxygen

How many grams are in 68.2 molecules of br2?

On the periodic table, elements are arranged by which of the following. a. mass numbers. b. increasing atomic number. c. alphabetical order. or d. density

Calcium carbonate decomposes at high temperatures to give calcium oxide and carbon dioxide as shown below. caco3(s) cao(s) + co2(g) the kp for this reaction is 1.16 at 800°c. a 5.00 l vessel containing 10.0 g of caco3(s) was evacuated to remove the air, sealed, and then heated to 800°c. ignoring the volume occupied by the solid, what will be the mass of the solid in the vessel once equilibrium is reached?