Final answer:
To calculate the number of grams in 7.18 x 10^24 ions of Mg, convert the given number of ions to moles using Avogadro's number, and then use the molar mass of Mg to convert moles to grams. The correct answer is option d) 56.02 grams.
Step-by-step explanation:
To calculate the number of grams in 7.18 x 10^24 ions of Mg, you need to convert the given number of ions to moles, and then use the molar mass of Mg to convert moles to grams.
First, convert 7.18 x 10^24 ions to moles using Avogadro's number (6.022 x 10^23 ions/mol).
7.18 x 10^24 ions * (1 mol / 6.022 x 10^23 ions) = 11.91 moles
Next, use the molar mass of Mg (24.305 g/mol) to convert moles to grams.
11.91 moles * (24.305 g/mol) = 289.43 grams
Therefore, the correct answer is option d) 56.02 grams.