If 20 grams of calcium combines completely with 16 grams of sulfur to form a compound, what

is the percent composition of calcium in the compound?

55.56% of Ca

Explanation:

Percent composition is a therm in chemistry defined as the ratio by mass between an element and the compound formed from this element.

In the problem, 20g of Ca are combined with 16g of S to form a compound. The mass of the compound is:

20g + 16g = 36g

Thus, percent composition of calcium is:

20g Ca / 36g × 100 = 55.56% of Ca

the grams   of   barium that   are in   2.3 x 10^23   atoms of barium   is   52.4 g (answer c)

    calculation

mass = moles   of ba   x molar   mass of ba

  molar mass of ba from periodic table=   137.3 g/mol

  use the   avogadro's law   constant   to   calculate the moles of barium

  that   is     1 mole =   6.02   x 10^23 atoms

                    ? moles = 2.3 x 10^23   atoms

by cross   multiplication

=(1 mole   x 2.3x 10^23 atoms)   / 6.02   x10^23 atoms)=   0.382   moles

mass   is therefore = 137.3   g/mol x 0.382 mol = 52.4 ( answer c)

explanation:

can you list the answers so i can answer