Answer: 122 moles
Procedure:
1) Convert all the units to the same unit
2) mass of a penny = 2.50 g
3) mass of the Moon = 7.35 * 10^22 kg (I had to arrage your numbers because it was wrong).
=> 7.35 * 10^22 kg * 1000 g / kg = 7.35 * 10^ 25 g.
4) find how many times the mass of a penny is contained in the mass of the Moon.
You have to divide the mass of the Moon by the mass of a penny
7.35 * 10^ 25 g / 2.50 g = 2.94 * 10^25 pennies
That means that 2.94 * 10^ 25 pennies have the mass of the Moon, which you can check by mulitiplying the mass of one penny times the number ob pennies: 2.50 g * 2.94 * 10^25 = 7.35 * 10^25.
5) Convert the number of pennies into mole unit. That is using Avogadros's number: 6.022 * 10^ 23
7.35 * 10^ 25 penny * 1 mol / (6.022 * 10^ 23 penny) = 1.22* 10^ 2 mole = 122 mol.
Answer: 122 mol
Answer:
The percentage by mass of element X is 25 %.
The percentage by mass of element Y is 75 %
Explanation:
X + Y ⇒ XY
3.5 g of element X + 10.5 g of element Y = 14g in total
⇒Element X : 3.5g / 14g = 0.25 ⇒ x 100 % = 25 %
⇒Element Y : 10.5 / 14 = 0.75 ⇒ x 100 % = 75 %
The percentage by mass of element X is 25 %.
The percentage by mass of element Y is 75 %
Depth where light intensity falls to one percent<span> of that at the surface, called the euphotic depth</span>
