1. Given an element's atomic number and mass number, how can you tell the number of protons and neutrons in its nucleus? Number of protons = mass number; number of neutrons atomic number - mass number
Number of protons = atomic number; number of neutrons = mass number + atomic number
Number of protons = atomic number; number of neutrons = mass number - atomic number

Two 1.20-m nonconducting wires meet at a right angle. one segment carries + 2.50 µc of charge distributed uniformly along its length, and the other carries - 2.50 µc distributed uniformly along it, as shown in fig. 21.50. ( a. find the magnitude and direction of the electric field these wires produce at point p, which is 60.0 cm from each wire. ( b. if an electron is released at p, what are the magnitude and direction of the net force that these wires exert on it?