2. Elements in the same group have similar properties because they have O the same number of protons O the same number of valence electrons O the same number of energy levels with electrons O the same total number of electrons

What is the fate of the electrons that interact with a specimen in an electron microscope?

What is required for an electric charge to flow through a wire? zero resistance in the wire a balance of electric potential high resistance in the wire a difference in electric potential

Arotating space station is said to create “artificial gravity”—a loosely-defined term used for an acceleration that would be crudely similar to gravity. the outer wall of the rotating space station would become a floor for the astronauts, and centripetal acceleration supplied by the floor would allow astronauts to exercise and maintain muscle and bone strength more naturally than in non-rotating space environments. if the space station is 200 m in diameter, what angular velocity would produce an “artificial gravity” of 9.80 m/s^{2} 2 at the rim?