Question

A gold nucleus (radius r) is represented by a symbol Au. Taking e as elementary charge and Eo as permitivity of free space. What is the electric field strength at the surface of an isolated gold nucleus? Remember to show your work..

















9

Answer 1

Answer:

Let r be the radius of the gold and E be the electric field at r/2.

If ρ is the volume charge density, Q=Ze=ρ.

3

4

πr

3

...(1)

using Gauss's law, E.4π(r/2)

2

=

ϵ

0

Q

enclosed

=

ϵ

0

ρ.

3

4

π(r/2)

3

or E=

8πϵ

0

r

2

Ze

using (1)

E=

8×3.14×8.854×10

−12

×49×10

−30

79×1.6×10

−19

=1.16×10

21

NC

−1