Find electric charge using

Question

The average distance of the electron from the proton in the hydrogen atom is 0.51 x 10e-10 m. What is the electric field from the proton's charge at the location of the electron? (Given: ke = 8.99 x 10e9 Nm2/C2)

(Given: e = 1.6 x 10e-19 C)

I've done harder problems bur for some reason I can't get this simple one.

I tried to use [E=ke q/r2] but I get the wrong answer.

Answer 1

Were you, by chance, thinking of "ke" as "k*e"?

If so, think of it as k = 8.99×10^9 (N*m²)/C² (instead of ke = ...).

e is the elementary charge and is used for q in this problem.

Here's what I got:

E = k*(q/r²)

E = [8.99×10^9 (N*m²)/C²] * [(1.6×10^-19 C) / (0.51×10^-10 m)²]

E = [8.99×10^9 (N*m²)/C²] * [(1.6×10^-19 C) / (2.601×10^-21 m²)]

E = [8.99×10^9 (N*m²)/C²] * [61.5148 C/m²]

E = 5.53 × 10^11 N/C