Question
Lithium and potassium are in the same group of the periodic table. Figure 3 represents the electronic structures of a lithium atom and of a potassium atom. Lithium atom Li Figure 3 Potassium atom xx xx K is xer ive two reasons why potassium is more reactive than lithium. __
Answer
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(333 Votes)
Olwen
Master · Tutor for 5 years
Answer
1. Potassium is more reactive than lithium because potassium's valence electron is in a higher energy level.2. Potassium's outermost electron is further away from the nucleus and is therefore more easily lost during reactions.
Explanation
The reactiveness of an atom is mostly dependent on how easily it can lose or gain electrons. This is largely influenced by the energy levels which these electrons inhabit. In the case of lithium and potassium, they both belong to the same group on the periodic table (Group 1: Alkali Metals). Elements in this group have one electron in their outermost energy level and tend to lose that single electron in chemical reactions. Although lithium and potassium have similar reactivity characteristics because they are in the same group, potassium is further down the periodic table and its outermost electron resides in a higher principal energy level, further from the positively charged nucleus, therefore, held less tightly due to less electrostatic forces between electron (negative charge) and the nucleus (positive charge). 1) Potassium has its one valence electron (outermost electron) sitting in the fourth energy level (principal quantum level 4 or n = 4), compared to Lithium's valence electron, which is in the second energy level (n = 2). 2) Because this electron in potassium is in a larger orbit (higher energy level, further from the nucleus), it experiences less electromagnetive attraction to the positive core of the atom. Therefore, it is easier for potassium to lose this electron and thus can react faster. Lithium's outermost electron is in a smaller orbit (lower energy level, closer to the nucleus), and therefore experiences a stronger electromagnetive attraction to the positive core of the atom. Therefore, it is harder for lithium to lose this electron, and it won't react as quickly as potassium.