Which following shows elements in order of increasing atomic radius? Mg < Na < Be < Li Li < Be < Na < Mg Na < Mg < Li < Be Be < Li < Mg < Na

Answer 1

To determine the atomic radius, there are two rules.

One: The more electron shells there are, the larger the radius. This is determined by the group the element is in on the periodic table.

Two: If two atoms have the same amount of shells, the more with less electrons will have larger radius. Think of people trying to pack in the room. The less people the more spread out they will be, but the more people that come, people will move closer to make space.

Another way to think about it if it is easier is to look at the periodic table. The atomic radius increases down the table ( going to larger group) and as you move to the right of the table (going to smaller period).

I am assuming the elements that you have listed are multiple choice options that copied weird. If the elements are Na, Mg, Be, and Li. The increasing order (smallest to largest) would be Be

Answer 2

This was focused on Shielding Effect; however, both atomic radius and shielding effect follow the same rules as one another. Once you understand one, it is far easier to figure out the other.