Answer
a.Ca or O
b. O or F
c. H or O
d. K or S
Work Step by Step
a. This question is really asking which element in each pair has the highest electronegativity value. Electronegativity generally increases when moving across a period from left to right and decreases when moving down a period. In this case, Oxygen is both to the right and above calcium. Therefore oxygen would have a greater attraction of electrons.
b. Fluorine is to the right of oxygen (fluorine has also the highest electronegativity value in the whole table), so it is definitely attracting electrons with a greater force.
c. Oxygen would attract electrons with a greater force because it has a greater electronegativity value (3.5) than that of hydrogen (2.1).
d. Sulfur is both to the right and above potassium. Therefore sulfur would have a greater attraction of electrons.
