To determine which element has the largest atomic radius, we need to examine the properties of the elements listed in the table from the periodic table.
The trend for atomic radius on the periodic table is that atomic radius increases as you move down a group (column) due to the addition of electron shells, and it decreases as you move from left to right across a period (row) due to the increasing nuclear charge pulling the electrons closer to the nucleus.
Given this trend, we focus on the elements listed in the table:
[tex]\[
\begin{tabular}{|c|c|}
\hline 1 & \\
$H$ & \\
\hline 3 & 4 \\
$Li$ & $Be$ \\
\hline 11 & 12 \\
$Na$ & $Mg$ \\
\hline 19 & 20 \\
$K$ & $Ca$ \\
\hline 37 & 38 \\
$Rb$ & $Sr$ \\
\hline 55 & 56 \\
$Cs$ & $Ba$ \\
\hline 87 & 88 \\
$Fr$ & $Ra$ \\
\hline
\end{tabular}
\][/tex]
Among these elements, the one that is located furthest down and to the left in the periodic table is Francium (Fr). Francium is in Group 1 (the leftmost column) and Period 7 (the bottom row), which places it at the bottom left of the elements listed. Following the periodic trends, Francium has the largest atomic radius.
Therefore, the element with the largest atomic radius is Francium (Fr) with the atomic number 87.
