Final answer:
Among the options given, Mg (magnesium) has the largest atomic radius because it is further to the left and lower on the periodic table compared to Fe (iron), Zn (zinc), and Si (silicon).
Step-by-step explanation:
The student has asked which of the following elements has the largest atomic radius: Fe (iron), Zn (zinc), Mg (magnesium), or Si (silicon). To answer the question, we look at the periodic table and apply the knowledge that atomic radius generally increases as we move from top to bottom and from right to left within the table. Comparing the elements in question, Mg is located in the second group and third period, Fe is in the eighth group and fourth period, Zn is in the twelfth group and fourth period, and Si is in the fourteenth group and third period.
Based on their positions in the periodic table, we can predict that Fe has a smaller atomic radius than Mg because it is further to the right and in a higher period. Similarly, Zn has a smaller atomic radius than Fe because it is also further to the right in the same period. Si, being in the same period but further to the right than Mg, would also have a smaller atomic radius. Therefore, among the given options, Mg (magnesium) would have the largest atomic radius.