<span>They are emitted by the unstable nuclei of certain atoms.
That's all I could find out; Sorry I couldn't be more of an help.</span>
Answer:
y = 10.2 m
Explanation:
It is given that,
Charge, 
It is placed at a distance of 9 cm at x axis
Charge, 
It is placed at a distance of 16 cm at x axis
We need to find the point on the y-axis where the electric potential zero. The net potential on y-axis is equal to 0. So,

Here,

So,

Squaring both sides,

So, at a distance of 10.2 m on the y axis the electric potential equals 0.
I would say 150 joules, i don't know if its right though check
Maybe this will help you in a way,<span> some physical properties include: appearance, texture, color, odor, melting point, boiling point, density, solubility, polarity, and many others.
- hope this helps you well .</span>