Please help; chemistry

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.

What is the name of the enzyme that forms at the start of transcription?

Which words or phrases identify layers of groundwater? check all that apply. water table kettle lake saturation zone underground lake sinkhole will give brainiest, answer quickly.