Question

Arrange the following elements in order of increasing atomic radius : Rb , K , Na , Li

Answer 1

Generally, atomic radii have this property on the periodic table: as you go down or left, the radius of an atom gets larger. 

With this logic, let's apply this to the problem above. Li is on the highest part of the table compared to the other elements. Below it is Na, then K, then Rb. From our rule, we know that as we go down on the table, the atomic radius gets larger. 

Thus, Li has the smallest radius, and Rb has the largest radius.

FINAL ANSWER: Li, Na, K, Rb

Answer 2

Answer:

Li < Na < K < Rb

Explanation:

The atomic radius is increases when more external atomic levels are filled with electrons. In the periodic table, the higher the period, the more atomic levels that element has completed. So:

• Li: period 2
• Na: period 3
• K: period 4
• Rb: period 5

Given the previous explanation, the increasing order of atomic radious will be:

Li < Na < K < Rb