Answer is: there are 3.011·10²³ atoms of calcium.

n(Ca) = 0.50 mol; amount of substance(calcium).
Na = 6.022·10²³ 1/mol; Avogadro's constant or number.
N(Ca) = n(Ca) · Na.
N(Ca) = 0.50 mol · 6.022·10²³ 1/mol.
N(Ca) = 3.011·10²³; number of calcium atoms.
The mole is an SI unit which measures the number of particles in substance. One mole is equal to 6.022·10²³ atoms.

6 0

3 years ago

A molecule of carbon dioxide (co2) is formed when one atom of carbon (atomic number 6) is covalently bonded with two atoms of ox

xxMikexx [17]

Carbon must share 4 electrons total with the the two Oxygen atoms in order to fill it's outer electron shell, and each Oxygen atom must share 2 electrons with the Carbon atom to fill their electron shells. Therefore, in total 8 electrons must be shared (4+2+2=8)

4 0

3 years ago