How many moles are in 20.5 grams of Calcium (Ca)? (1pt) A)762.45 moles
B)1 mole
C)2 moles
D)0.5 moles

Number of moles in 20.5 grams of calcium (Ca) = 0.5 moles (Approx.)

Explanation:

Given:

Amount of calcium (Ca) = 20.5 grams

Find:

Number of moles in 20.5 grams of calcium (Ca)

Computation:

Number of moles = Gram weight / Atomic weight of substance

We know that, Atomic weight of calcium (Ca) is 40.078 u

Number of moles in 20.5 grams of calcium (Ca) = Amount of calcium (Ca) / Atomic weight of calcium (Ca)

Number of moles in 20.5 grams of calcium (Ca) = 20.5 / 40.078

Number of moles in 20.5 grams of calcium (Ca) = 0.511

Number of moles in 20.5 grams of calcium (Ca) = 0.5 moles (Approx.)

a. they are both space stations

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the mantle

explanation:

earth is divided into three layers: the crust or the outermost layer on which we live; the underlying, middle layer - the mantle - and the core (the innermost layer of earth).