The decomposition of so3 to so2 gas and o2 gas can be described in the balanced chemical equation:
2so3(g) = 2 so2 (g) + 02(g).
so assuming a complete reaction, the ratio of so2 gas to total products is 2/3 while that of 02 is 1/3.
Subtracting water's water vapor pressure, 760-40 mm hG = 720 mm Hg.
then the products partial pressures are
so2 = 2/3 * (720) = 480 mm Hg.
o2 = 720-480 = 240 mm Hg.
Answer: 
Explanation:
According to the law of conservation of mass, mass can neither be created nor be destroyed. Thus the mass of products has to be equal to the mass of reactants. The number of atoms of each element has to be same on reactant and product side. Thus chemical equations are balanced.
The balanced chemical equation for reaction of potassium superoxide with carbon dioxide to produce oxygen and potassium carbonate will be:

2) generating power by using fossil fuels is harvesting a non-renewable resource. The more you harvest = the less you have
PH = 0.1289<span> for </span>1.50<span> M solution of weak acid with Ka value of </span><span>.73</span>
Answer:
A. there is an isotope of lanthanum with an atomic mass of 138.9
Explanation:
By knowing the different atomic masses of both Lanthanum atoms, we can not tell anything about their occurence in nature. Therefore, all the last three options are incorrect. Because, the atomic mass does not tell anything about the availability or natural abundance of an element.
Now, the isotopes of an element are those elements, which have same number of electrons and protons as the original element, but different number of neutrons. Therefore, they have same atomic number but, different atomic weight or atomic masses.
Hence, by looking at an elements having same atomic number, but different atomic masses, we can identify them as isotopes.
Thus, the correct option is:
<u>A. there is an isotope of lanthanum with an atomic mass of 138.9.</u>