Assuming that air contains 23 percent by weight of oxygen. Calculate the volume of air at NTP required for the complete combustion of 1kg of coal containing 90percent carbon and 5percent hydrogen (density of air=1.296gm/litre at NTP)

Look at the bean data from days 4–6. use these data to explain how natural selection changed the number of dark red walking beans over time. writing part

6. what does the symbol ah stand for? o one calorie given off by a reaction the specific heat of a substance the heat capacity of a substance the heat of reaction for a chemical reaction

Which is a chemical property of iron? a. it forms iron oxide (rust) when exposed to moisture and air. b. it is a gray–black metal that is hard to the touch. c. it has a melting point of 2795°f (1536°c). d. it is a good conductor of heat