Which of the following is an example of symbiosis?

Which best describes how johannes kepler developed his laws of planetary motion

Asample of aluminum foil contains 8.60 × 1023 atoms. what is the mass of the foil?

Select all of the statements which are true. electrons are located in shells or orbits around the atom. electrons orbit slowly around the atom. electrons travel in one flat path around the nucleus of an atom. the valence of an atom is determined by the number of electrons in the atom's outermost shell.