What part of the ocean floor does the center split represet

Which of these conditions most likely produces an unstable isotope?

In the reaction between a crushed antacid tablet and vinegar what gas is emitted

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.