two electrons (each with the charge of 1.6 x 10^ -19 c) are seperated by a distance of 5.4 x 10^ -5 c what is the electric force pushing them apart?

The electric force between two charges is:

F = (9 x 10⁹) Q₁ Q₂ / D²

F is the force, in Newtons

Q₁ and Q₂ are the two charges, in Coulombs

D is the distance between them, in meters

I'm going to assume that the first little 'c' in the question stands for "Coulombs", and the second little 'c' stands for "centimeters".  And now, I'll proceed to answer the question that I've just invented.

For these two electrons:

F = (9 x 10⁹) (1.6 x 10⁻¹⁹) (1.6 x 10⁻¹⁹) / (5.4 x 10⁻⁷)²

F = (9 x 1.6 x 1.6 x 10⁻²⁹) / (5.4² x 10⁻¹⁴)

F = (23.04 / 29.16) x 10⁻¹⁵

F = 7.9 x 10⁻¹⁶ of a Newton

EACH electron feels that same force, pushing it away from the other electron.

1 a

2 b

3 b

4 d

5 d

6 d

explanation:

wavelength divides in half and speed stays the same.