Question

the table below shows the distance between the atoms in an atom pair. all four pairs of atoms have the same amount of electric charge.
pair of atoms | distance between the atoms
a & b | 5 units
c & d | 3 units
p & q | 7 units
x & y | 6 units
which pair of atoms are repelled from each other with the most force?
a. pair x & y
b. pair c & d
c. pair a & b
d. pair p & q

Explanation:

According to Coulomb's law for electric force (in the context of atomic interactions, applicable here as charges are equal), the electric force between two charged objects is inversely proportional to the square of the distance between them ($F \propto \frac{1}{r^2}$ when charges are constant). So, the smaller the distance ($r$), the larger the repulsive force. Among the pairs, C & D have the smallest distance (3 units), so they experience the most repulsive force.

Answer:

B. Pair C & D