One of two identical metal spheres has a charge of +q and the other sphere has a charge of –q. The spheres are brought together momentarily and then separated. Compared to the total charge on the two spheres before contact, the total charge on the two spheres after contact is (a) less, and each sphere will have a charge of –q
(b) greater, and each sphere will have a charge of +q
(c) the same and each sphere will have a charge of 0

adding a(n) to an electric circuit would increase the magnetic field around a wire;

b. solenoid

a solenoid is a type of electromagnet whose purpose is to generate a controlled magnetic field.

if the purpose of the solenoid is instead to impede changes in the electric current, a solenoid can be more specifically classified as an inductor rather than an electromagnet.

molecules are free to separate from each other and will take on the shape of the container. molecules move completely at random and high speeds. they vibrate in a fixed position and do not move around much. molecules expand to the edge of their container.