How can electrical current produce a magnetic field, and how can a magnetic field produce an electrical current?

In physics the desire of an object to keep doing what it is doing is termed?

What is the electric force acting between two charges of -0.0045 c and -0.0025 c that are 0.0060 m apart? use fe=kq1q2/r^2 and k = 9.00 x 10^9 n*m^2/c^2 a. 1.7 x 10^7 n b. -1.7 x 10^7 n c. -2.8 x 10^9 n d. 2.8 x 10^9 n

Achlorine atom has 17 protons and 18 neutrons. what is its mass number? what is its atomic number?