When an oxygen atom forms an ion, it gains two electrons. What is the electrical charge of the oxygen ion? -2 -1 +1 +2

Which statement best explains why cells were observed in more detail using a compound microscope than a simple microscope? a compound microscope has greater magnification ability than a simple microscope. the compound microscope was invented before the simple microscope. a compound microscope is much easier to manufacture than a simple microscope. compound microscopes were more common than simple microscopes.