In order to solve this problem, we will first need to find the electric field at the origin without the 3rd charge
E1 = (9x10^9)(13.4x10^-9)/(9.4x10^-2)^2 = 13648.7 V/m towards the negative y-axis
E2 = (9x10^9)(4.23x10^-9)/(4.99x10^-2)^2 = 15289.1 V/m towards the positive x-axis
The red arrow shows the direction of which the electric field points.
To make the electric field at the origin 0, we must find a location where q3 = the magnitude of q1 and q2
Etotal = sqrt(E1+E2) = 20494.97 V/m
E3 = 20494.97 = (9x10^9)(14.23x10^-9)/(d)^2
d = 0.079 m = 7.9 cm
Answer:
Explanation:
Given
Electric Field strength 
charge of electron 
Force on the charge particle is given by



but this force will be acting in the direction opposite to the direction of Electric field because electron is negatively charged
The answer is A. Hope this helps. :)
During a single replacement, the Zn and H will switch places. That means the product formed will be ZnCl and H2.