Question

The table below shows four pairs of atoms and the electric charge of each atom. The atoms in each pair are located the same distance from each other.

Pair Atom A Atom B
W +4 +6
X -5 -5
Y +4 +3
Z -4 -5

Which pair of atoms is experiencing the strongest electric force?
A.
Pair X
B.
Pair Y
C.
Pair W
D.
Pair Z

Answer 1

Answer: A (Pair X).

Reason: Coulomb’s law gives F ∝ |q1·q2|/r^2. All pairs are the same distance, so compare |q1·q2|:
- W: |4·6| = 24
- X: |−5·−5| = 25
- Y: |4·3| = 12
- Z: |−4·−5| = 20

Pair X has the largest product (25), so it feels the strongest force.