Question

1. rank the following elements by decreasing atomic radius: antimony, indium, xenon, zirconium

xenon,antimony,indium,zirconium.

1. rank the following elements by decreasing atomic radius: barium, mercury, tungsten, polonium

mercury, polonium, tungsten,barium
10.rank the following elements by decreasing atomic radius: boron, thallium, gallium, indium

Explanation:

Step1: Recall atomic - radius trend

Atomic radius increases down a group and decreases across a period.

Step2: Analyze the positions of elements

Boron (B) is in Group 13, Period 2; gallium (Ga) is in Group 13, Period 4; indium (In) is in Group 13, Period 5; thallium (Tl) is in Group 13, Period 6.

Step3: Rank the elements

Since atomic radius increases down a group, the order of decreasing atomic radius is thallium, indium, gallium, boron.

Answer:

thallium, indium, gallium, boron