Anormal nitrogen atom has seven protons and seven neutrons. which of the following atoms are isotopes of nitrogen? check all that apply

a: an atom with eight protons and eight neutrons

b: an atom with seven protons and six neutrons

c: an atom with seven protons and nine neutrons

d: an atom with five protons and seven neutrons

Four point charges each having charge q are located at the corners of a square having sides of length a. find symbolic expressions for the following. (a) the total electric potential at the center of the square due to the four charges (use any variable or symbol stated above along with the following as necessary: ke.) vtotal= (b) the work required to bring a fifth charge p from infinity to the center of the square (use any variable or symbol stated above along with the following as necessary: w=