arrange in increasing atomic radius: xenon, tellurium, rubidium, antimony

arrange in increasing atomic radius: xenon, tellurium, rubidium, antimony

The correct answer and explanation is:

Correct Answer (in increasing atomic radius):
Xenon < Antimony < Tellurium < Rubidium

Explanation:

Atomic radius refers to the distance from the nucleus of an atom to the outermost electron shell. It generally increases down a group and decreases across a period on the periodic table. This trend is influenced by the number of electron shells and the effective nuclear charge acting on the electrons.

1. Xenon (Xe) is a noble gas found in Period 5, Group 18. Although it has more electron shells than some of the other elements listed, its electrons are tightly held due to a high effective nuclear charge and a full outer shell. As a result, xenon has a relatively small atomic radius among heavier elements.
2. Antimony (Sb) is a Group 15 element in Period 5. It has a larger atomic radius than xenon because it has a lower nuclear charge attraction on the outer electrons and does not have a full valence shell. However, it still experiences some electron attraction due to being in the same period as xenon.
3. Tellurium (Te) is in Group 16 and Period 5. It lies to the left of antimony and has a slightly larger atomic radius because atomic radius increases moving leftward across a period. Even though they are close in size, tellurium’s lower nuclear charge causes its electrons to be held less tightly.
4. Rubidium (Rb) is located in Group 1 and Period 5. It has the largest atomic radius among the four because it has only one valence electron far from the nucleus. The shielding effect from inner electrons reduces the pull of the nucleus on the outer electron, causing the radius to expand significantly.

Thus, considering periodic trends and electron configurations, the correct increasing order of atomic radius is: Xenon < Antimony < Tellurium < Rubidium.