To take the percent by mass of this element, we use the
formula:
% mass = (mass of element / mass of ore) * 100%
% mass = (47.5 g / (660 kg * 1000 g / kg)) * 100*
<span>% mass = 7.20 x 10^-3 %</span>

The Balanced equation will be :

The Coefficients are :
_____________________________

Answer:
35.6 liters at STP
Explanation:
The molar mass of carbon dioxide is about 44.01 g/mol. The volume of a mole of ideal gas at STP is 22.4 L, so the volume of 70.0 g will be ...
(70.0g)/(44.01 g/mol)·(22.4 L/mol) ≈ 35.6 L
The atomic radium increases to the left and downwards on the periodic table.
By that logic, Se has the largest radius.