Classify the following as a pure substance or a mixture. If pure, then identify whether it is an element or a compound. If a mixture, identify whether it is homogeneous or heterogeneous. a) CO2 b) Iced Tea c) Dirt d) NaCl e) Oatmeal Raisin Cookies f) Chicken Tikka Masala g) Fe h) Sulfur dioxide (SO2)

Consider hydrogen in an excited state n = 5n=5 that emits photons to reach the ground state. there are various possible transitions other than straight to the ground state that can occur; for example, it can drop to the n = 3n=3 state followed by the n = 3n=3 to the ground state transition. which of the possible transitions will result in the emission of a photon in the visible region?

Awoman's basketball has a circumference between 28.5 and 29.0 inches and a maximum weight of 20 ounces (two significant figures). what are these specifications in units of centimeters and grams?

28. which is not a reason that water is used to store spent fuel rods from nuclear power plants? water increases the speed of the chain reaction in the fuel rods. water protects nuclear power plant workers from the high temperature and radiation of the fuel rods. water acts as a radiation shield to reduce the radiation levels. water cools the spent rods. salts action