Ozone is concentrated in earth’s atmosphere at an altitude of 20 to 35 kilometers. Which atmosphere later contains the greatest concentration of ozone

Achemist has dissolved a certain substance in water. the chemist knows that more of the substance could be dissolved into the water before it stops dissolving. therefore

An unknown substance is a white solid at room temperature and has a melting point of 78 °c. which of the following substances is most likely to be the identity of the unknown sample? a. naphthalene, a molecular solid with the formula c10h8 b. silica, a network solid held together by covalent bonds with the formula sio2 c. calcium chloride, an ionic compound with the formula cacl2 d. water, an molecular compound with the formula h2o

All chemicals, even safe chemicals, such as sodium chloride( table salt), are toxic if exposure is high enough. (true or false)