Question

which arrangement of the following period 5 elements, from left to right, orders them with respect to their atomic size, from smallest to largest?
o te, sb, in, sr, rb
o in, rb, sb, sr, te
o rb, sr, in, sb, te
o in, sb, te, rb, sr

Explanation:

Step1: Recall atomic - size trend

Atomic size decreases across a period from left to right. This is because the number of protons in the nucleus increases, resulting in a greater nuclear charge that pulls the electrons closer to the nucleus.

Step2: Identify element positions

Rb (Rubidium), Sr (Strontium), In (Indium), Sb (Antimony), and Te (Tellurium) are all in Period 5. Their atomic numbers are 37 (Rb), 38 (Sr), 49 (In), 51 (Sb), and 52 (Te) respectively.

Step3: Order elements

Based on the atomic - size trend across a period, the order of these elements from smallest to largest atomic size (left - to - right) is Te, Sb, In, Sr, Rb.

Answer:

Te, Sb, In, Sr, Rb