Answer
a. Rb, K, Na
b. Ga, B, O
c. Br, Cl, F
d. S, O, F
Work Step by Step
The trend of electronegativity tends to increase as you go from left to right on the periodic table; also, electronegativity decreases as you go from top to bottom on the periodic table.
a. Rb, K, Na: All three elements are in the alkali metal group of the periodic table, so we measure electronegativity in a vertical direction. sodium (Na) is the topmost element, so it is the most electronegative. Potassium (K) is the next element down, so it is second in electronegativity. Finally, rubidium (Rb), lying the lowest within this group, has the lowest electronegativity value. The trend for this set is determined by how far right on the periodic table each element is located.
b. Ga, B, O: Since gallium (Ga) is the lowest element among the three, it should have the lowest electronegativity. Then, we look at boron (B) and oxygen (O), which lie in the same row (period), but since oxygen lies farther right, it has the higher electronegativity value.
c. Br, Cl, F: All three elements are in the halogen group of the periodic table, so we measure electronegativity in a vertical direction. Fluorine (F) is the topmost element, so it is the most electronegativity. Chlorine (Cl) is the next element down, so it is second in electronegativity. Finally, bromine (Br), lying the lowest within this group, has the lowest electronegativity value.
d. S, O, F: Sulfur (S), lying farthest left and the lowest down, would have the least electronegative value. oxygen (O), lying farther right and farther up from sulfur, would have the second highest electronegative value among the three. Finally, fluorine (F), which is the highest and farthest right on the periodic table of the three, would have the highest electronegativity value.
