Arrange the following ions in terms of increasing atomic radius (arrange the increasing from left [lowest] to right [largest]):
P3-, Cl-, K+, S2-
To arrange the given ions in terms of increasing atomic radius, we need to consider their positions in the periodic table. Atomic radius generally increases as you move down a group (column) in the periodic table and decreases as you move across a period (row) from left to right.
Let's check the positions of the ions in the periodic table:
P3- (phosphide ion) - Phosphorus (P) is in group 15 (column 15) of the periodic table.
Cl- (chloride ion) - Chlorine (Cl) is in group 17 (column 17) of the periodic table.
K+ (potassium ion) - Potassium (K) is in group 1 (column 1) of the periodic table.
S2- (sulfide ion) - Sulfur (S) is in group 16 (column 16) of the periodic table.
Now, let's arrange these ions in terms of increasing atomic radius:
K+ < Cl- < S2- < P3-
Explanation:
K+ (potassium ion) has the smallest atomic radius because it is a cation (positively charged ion) and has lost an electron. When an electron is lost, the outermost electron shell becomes smaller and the overall size of the ion decreases.
Cl- (chloride ion) is larger than K+ because it is an anion (negatively charged ion) and has gained an extra electron. This extra electron increases the repulsion between the electrons, causing the electron cloud to spread out and the overall size of the ion to increase.
S2- (sulfide ion) has a larger atomic radius than Cl- because it is in the same period (row) but has gained two extra electrons. The added repulsion between the electrons results in a larger ionic radius.
P3- (phosphide ion) has the largest atomic radius among the given ions because it is in the same period as S2- but has gained three extra electrons. Again, this added electron-electron repulsion leads to a larger ionic radius.
Therefore, the correct arrangement of the ions in terms of increasing atomic radius is: K+ < Cl- < S2- < P3-.