How do the nuclei of covalently bonded atoms help keep the bond together? Neutral particles in the nucleus provide enough mass that the force of gravity holds the atoms together.
Neutral particles in the nucleus can become positive or negative in order to balance the charges.
Positive particles in the nucleus change into negative particles that enter electron shells.
Positive particles in the nucleus are attracted to shared electrons, so the atoms stay close together.

What is the most useful equation for electric power?

As you are trying to move a heavy box of mass m, you realize that it is too heavy for you to lift by yourself. there is no one around to , so you attach an ideal pulley to the box and a massless rope to the ceiling, which you wrap around the pulley. you pull up on the rope to lift the box. use g for the magnitude of the acceleration due to gravity and neglect friction forces. once you have pulled hard enough to start the box moving upward, what is the magnitude f of the upward force you must apply to the rope to start raising the box with constant velocity? express the magnitude of the force in terms of m, the mass of the box.

If you place a magnet under a clear dish, and sprinkle iron fillings over it, above what part of the magnet will most of the fillings gather