Halogens

The first compound microscope was made in which of the following? The first compound microscope was developed in which year? The first compound microscope was developed by whom? The magnification power of first compound microscope was? Which of the following is increase in the apparent size of an object in microscopy? Which of the following is the measure of clarity of an image? The elements of VII group of the periodic table are generally called________? Halogens occur as ________ both in the earth's crust and in sea-water? The colour of chlorine gas is ________? Chlorine oxidizes an aqueous solution of ferrous chloride to ________? Chlorine reacts with dilute alkali in cold state to form _________ and chlorides? Hypochlorous acid is an unstable conpound and decomposes gradually in the presence of sunlight to produce?