To determine the order of the atomic radii of the elements C (Carbon), Cs (Cesium), Al (Aluminum), and S (Sulfur), we need to consider periodic trends in the periodic table.
Understanding Atomic Radii: The atomic radius is the distance from the center of the nucleus of an atom to the outermost electron shell. It is affected by two main trends:
Atomic radius decreases across a period (from left to right) due to increasing nuclear charge, which pulls electrons closer to the nucleus.
Atomic radius increases down a group (from top to bottom) because each successive element has an additional electron shell.
Position in the Periodic Table:
Carbon (C): Located in the 2nd period and 14th group.
Sulfur (S): Located in the 3rd period and 16th group.
Aluminum (Al): Located in the 3rd period and 13th group.
Cesium (Cs): Located in the 6th period and 1st group.
Trend Analysis:
C and S: Since S is further to the right in the same period as Al, its radius is smaller than Al.
Al and Cs: Cs is much lower down the group, which means it has more electron shells, leading to a significantly larger atomic radius.
The increasing order from smallest to largest atomic radii is C < S < Al < Cs.
Conclusion: The correct order of atomic radii is C < S < Al < Cs, which confirms that the provided correct answer is indeed accurate.
