Q106 E - Chemistry (OpenStax)

Question

Which halogen has the highest ionization energy? Is this what you would predict based on what you have learned about periodic properties?

Step-by-Step Solution

Answer

Thus, an element at the top of the group will have the highest ionization energy.

Step 1: Define Ionization Energy

Ionisation Energy is the least amount of energy   that is required to eject the most loosely bound electron of an isolated gaseous atom, positive ion, or molecule.

Step 2: Which halogen has the highest ionization energy:

Ionization energy is the amount of energy required for a molecule to lose an electron from its last shell.

 If we observe a group of halogens in the Periodic table of elements, we can tell that the size of an element increases from top to the bottom of the group. 

The distance between the farthest electron and the core increases with the size of the atom, while ionization energy decreases.

 Thus, an element at the top of the group will have the highest ionization energy.