Answer: The law of conservation of mass is reffering to the fact that energy cannot be created or destroyed. So when you speak about atoms not being created or destroyed it is the same thing. Unless you're talking about an atomic bomb where the atoms are split.
Answer: B
Explanation:
There is an atom of one type of element and then two atoms of another type of element.
A, I believe it is 810liters of oxygen! Please correct me if im wrong
The chemical reaction equation for this is
XeF6 + 3H2 ---> Xe + 6HF
Assuming gas behaves ideally, we use the ideal gas formula to solve for number of moles H2 with T = 318.15K (45C), P = 6.46 atm, V = 0.579L. Then we use the gas constant R = 0.08206 L atm K-1 mol-1.
we get n = 0.1433 moles H2
to get the mass of XeF6,
we divide 0.1433 moles H2 by 3 since 1 mole XeF6 needs 3 moles H2 to react then multiply by the molecular weight of XeF6 which is 245.28 g/mole XeF6.
0.1433 moles H2 x

x

= 11.71 g XeF6
Therefore, 11.71 g of XeF6 is needed to completely react with 0.579 L of Hydrogen gas at 45 degrees Celcius and 6.46 atm.
Blue is the color that can be best absorbed, as orange is the color seen.