Question
Is the outer electron in potassium more or less strongly attracted to the positive nucleus than the outer electron in sodium is? less
Answer
4.4
(207 Votes)
Garrett
Master · Tutor for 5 years
Answer
less
Explanation
The attraction between an outer electron and the nucleus is determined by the effective nuclear charge, which is the net positive charge experienced by an electron in a polymount-electron atom. If the atom has more electrons, there will be more electron-electron repulsions, which means that the outermost electrons will experience a smaller effective nuclear charge, thereby making them less attracted to the nucleus. This is the reason why atomic size usually increases as you move down a group in the periodic table - even though the nuclear charge is increasing, the number of electron shells or energy levels is also increasing, causing a decrease in the effective nuclear charge.Potassium is below sodium in the periodic table and thus has more electron shells than sodium does. Consequently, its outer electron experiences more electron-electron repulsions and hence experiences a smaller effective nuclear charge and is less attracted to the nucleus.