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There is about 70mg of astatine in the outermost 1 mile of earths crust. How many moles and how many atoms of astatine is this

User Umpljazz
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Final answer:

There are approximately 0.333 millimoles (0.333 x 10^-3 moles) and 2.01 x 10^20 atoms of astatine in the specified portion of Earth's crust.

Step-by-step explanation:

The amount of astatine in the crust of the Earth can be converted to moles and atoms using Avogadro's number, which is 6.022 x 1023 particles per mole. To find the number of moles of astatine in 70mg, we use the formula:

moles = mass (in grams) ÷ molar mass (in grams per mole).

The molar mass of astatine (At) is approximately 210 g/mol (this is a common average value; the actual molar mass can differ slightly based on isotopic composition). Calculating the moles of astatine:

moles = 70 x 10-3 g ÷ 210 g/mol ≈ 0.333 x 10-3 mol.

To calculate the number of atoms, we multiply the number of moles by Avogadro's number:

atoms = moles x Avogadro's number

atoms = 0.333 x 10-3 mol x 6.022 x 1023 mol-1 ≈ 2.01 x 1020 atoms.

Therefore, there are approximately 0.333 millimoles (or 0.333 x 10-3 moles) and roughly 2.01 x 1020 atoms of astatine in the outermost 1 mile of Earth's crust.

User Jimmithy
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