Which atom or ion is the largest?

The elements with the largest atomic radii are located towards the left and bottom of the periodic table (i.e. at the bottom of Group 1). Thus, in theory, the largest atom should be Francium.

it is Francium

Explanation:

here is table 2-2:

country

percent of eligible voters that voted

rank

united states

44.9%

138

canada

60.1%

107

costa rica

84.6%

14

hungary

66.9%

82

japan

57.0%

118

egypt

27.7%

159

south africa

85.5%

10

ans is no, the data set cannot be plotted as a single circle graph