1. Analyze the Problem Known: periodic table information for four elements Unknown: which of the four has the __ 2. Solve for the unknown Use the __ to determine if the elements are in the same group or period. All four elements are in __ Order the elements from __ across the period. __ Determine the largest based on trends of __ 3. Evaluate the answer The __ in atomic radii have been correctly applied.

## Step 1: Analyze the Problem<br />The problem involves analyzing the periodic table to determine which of the four given elements has the largest atomic radius. The atomic radius is the distance from the nucleus to the outermost shell of an electron. This distance can vary depending on the type of bond and the element.<br /><br />## Step 2: Solve for the unknown<br />To solve this problem, we need to use the periodic table to determine if the elements are in the same group or period. All four elements are in the same period. We then order the elements from left to right across the period. The atomic radius decreases as we move from left to right across a period.<br /><br />## Step 3: Evaluate the answer<br />The trends in atomic radii have been correctly applied. The element with the largest atomic radius is the one that is furthest to the left in the period.