The first one? If not I just guessed
So as you may know atoms are neutral because the number of protons (+ charge) and the number of electrons( - charge) are the same so they cancel out. When a valence electron leaves an atom it will have a +1 charge because there is one less negative than positives or there is one more positive than negatives since a negative electron left. If a valence electron is added a -1 charge because there is now one more negative than positive!!!
hope that helps!!
X-ray)
because Electromagnetic waves are in act
Answer: v = 
Explanation: q = magnitude of electronic charge = 
mass of an electronic charge =
V= potential difference = 4V
v = velocity of electron
by using the work- energy theorem which states that the kinetic energy of the the electron must equal the work done use in accelerating the electron.
kinetic energy =
, potential energy = qV
hence, 
