Answer:
The magnitude is 
The direction is the positive x axis
Explanation:
From the question we are told that
The electric field is E = 450 V/m in the negative y ‑direction
The speed of the proton is
in the positive z direction
Generally the overall force acting on the proton is mathematical represented as

Now for the beam of protons to continue un-deflected along its straight-line trajectory then 
So

=> 
Generally from unit vector cross product vector multiplication

So the direction of B (magnetic field must be in the positive x -axis )
So

=> 
=>
=>
=> 
=>
The second part of the question can not be fully answered because it is not proven that there is or isn’t others life forms in this universe. personallyi think that there is but whatva
Ohm’s Law states that electrical current is proportional to voltage and therefore inversely proportional to resistance - V = I x R
Producing nuclear energy is far more environmentally friendly than burning fossil fuels. That is the main benefit.
The main risk is radiation. If the nuclear waste is not properly disposed of, it can leak radiation into the environment. Fortunately, this is not an issue since there are ways to deal with it. There is also the risk of a disaster like the Chernobyl incident, however that was mostly due to faulty reactor construction. However, reactors today are built to avoid such issues.