"Sodium is more reactive than potassium."
Answer whether the above statement is true or false.
If true enter 1, else enter 0.
Ionisation energies always decrease down a group. As we go down the group, the no. of shells increase as does the distance between the valence electrons and the nucleus. Although the no. of protons increases down the group, attraction between the nucleus and valence electrons decreases due to the shielding effect of more electrons in filled inner shells and also due to the increased distance between them. So it becomes easier to remove a valence elctron from an element at the bottom of a group than an element at the top.
Potassium has one more full shell of electrons between the nucleus and the outermost electron. Thus, in potassium, the outermost electron is better shielded from the attractive force of the nucleus. It follows, therefore, that this outermost electron is more easily lost than it is in sodium, so potassium can form K+ more readily than sodium can form Na+.
Larger radius = less "hold" on the valence electrons. Hence, potassium is more reactive than sodium.
