Question

Based on their locations on the periodic table, order the following elements from smallest atomic radius to largest atomic radius. (Use the appropriate <, =, or > symbol to separate substances in the list.)

Ca, Rb, Sr, Kr

Answer 1

Here we have to follow the periodic trends

1) As we down the group or column in the periodic table atomic radius increases (elements at bottom will have maximum radius)

2) As we move from left to right in the periodic table atomic radius decreases (elements at left will have maxium radius)

Keeping these two points in mind

Let us look a the positon of given atoms in periodic table (Look at periodic table)

Rb and Sr are comparitively at bottom and Rb is left to Sr

So Rb is has maximum radius among all followed by Sr (Rb > Sr)

Ca is left to Kr so Ca has maximum size and Kr is the smallest among all(Ca > Kr).

radius order from largest to smallest

Rb > Sr > Ca > Kr