I don't believe their is a legitimate answer for this question..
Answer:
306500 N/C
Explanation:
The magnitude of an electric field around a single charge is calculated with this equation:

With ε0 = 8.85*10^-12 C^2/(N*m^2)
Then:

E(0.89) = 306500 N/C
Answer:
The change in current at
is 
Explanation:
From the question we are told that
The resistance is 
The current is 
The change in voltage with respect to time is 
The change in resistance with time is 
According to ohm's law

differentiating with respect to time using chain rule

substituting value at R = 456


Potassium is the 19th element so it is B
Answer:magnetic and electric fields
Explanation: