Final answer:
To find the number of grams, you can use the molar mass of magnesium. The molar mass of magnesium is 24.30 g/mol. One mole of magnesium contains 6.022 x 10^23 atoms. So, to find the number of moles in 7.43 x 10^22 atoms, you can divide this by Avogadro's number: 7.43 x 10^22 atoms ÷ 6.022 x 10^23 atoms/mol = 0.123 mol. To find the number of moles of neon, divide the given mass by the molar mass: 68.4 g ÷ 20.18 g/mol = 3.39 mol.
Step-by-step explanation:
(a) How many grams of magnesium (Mg, 24.30 g/mol) are in 7.43 x 10^22 atoms of Mg?
To find the number of grams, you can use the molar mass of magnesium. The molar mass of magnesium is 24.30 g/mol. One mole of magnesium contains 6.022 x 10^23 atoms. So, to find the number of moles in 7.43 x 10^22 atoms, you can divide this by Avogadro's number: 7.43 x 10^22 atoms ÷ 6.022 x 10^23 atoms/mol = 0.123 mol.
Now, you can use the molar mass to convert moles to grams. Multiply the number of moles by the molar mass: 0.123 mol x 24.30 g/mol = 2.99 g. Therefore, there are 2.99 grams of magnesium in 7.43 x 10^22 atoms of Mg.
(b) How many moles of neon (Ne, 20.18 g/mol) are in 68.4 grams of Neon?
To find the number of moles, you can use the molar mass of neon. The molar mass of neon is 20.18 g/mol. Divide the given mass by the molar mass: 68.4 g ÷ 20.18 g/mol = 3.39 mol. Therefore, there are 3.39 moles of neon in 68.4 grams of Neon.