Answer:
1.97 × 10⁻¹⁸J
Step-by-step explanation:
Charge of an electron q = -1.9 × 10⁻¹⁹C
Length of one side of the equilateral triangle at whose corners electrons are placed d = 3.5 × 10⁻¹⁰m
Coulomb constant k = 8.99 × 10⁹Nm²/C²
electrostatic potential = (3 kq²) / d
= (3 × 8.99 × 10⁹ × (-1.6 × 10⁻¹⁹)²) / 3.5 × 10⁻¹⁰
= 1.97 × 10¹⁸J