Answer:
just click any of the buttons
Water is constantly being cycled between the atmosphere, the ocean and land. This cycling is a very important process that helps sustain life on Earth. As the water evaporates, vapors rise, and condense into clouds. The clouds move over land, and precipitation falls in the form of rain, ice, or snow.
First, find the number of moles of UF6
Avagadro's number = 6.023 x 10^23
Number of moles = 8.0 x 10^26 / Avagadro's number = 8.0 x 10^26 / 6.023 x 10^23 = 1.328 x 10³ moles
Molecular weight of UF6 = Molecular weight of U (238.02891) + Molecular weight of F6 (6 x 18.9984032) = 238.02891 + 113.9904192 = 352.0193292 g/mol
Therefore mass of 8.0 x 10^26 UF6 molecules = 352.0193292 g/mol x 1.328 x 10³ moles = 467.481669 x 10³ grams
The cost of painting the traffic sign of 7.065 square feet is approximately equal to 25 dollar.
<u>Explanation:</u>
The cost of painting the circular traffic sign is given as 3.50 dollar per square feet. The diameter of the traffic sign is 36 inch, then its radius will be 
inches.
But as the cost is given in unit of feet, we have to convert the radius from inches to feet.
1 inches = 0.0833 feet
18 inches = 18 × 0.0833 feet
So, the radius of the traffic sign will be approximately equal to 1.5 feet.
The area of the traffic sign will be 
square feet.
So, if the cost of painting 1 square feet of traffic sign is 3.50 dollar, then
cost of painting 7.065 square feet of traffic sign = 3.50 × 7.065 = 24.7 dollar.
Thus, the cost of painting the traffic sign of 7.065 square feet is approximately equal to 25 dollar.
The average molecular weight of the mixture can be calculated using this formula:
MWav = x1MW1 + x2MW2
Where x is the mass fraction of the components of the mixture, in this case, copper (63.546 g/mol) and zinc (<span>65.38 g/mol).
</span>
x1 = 7.36 / (7.36+0.51)=0.935
x2 = 0.51 / (7.36+0.51)=0.065
So,
MWav = 0.935(63.546) + 0.065(65.38) = 63.665 g/mol
