What evidence in lavoisier's twelve-day experiment showed that oxygen was chemically reacting (combusting) with substances? a) he obtained less of the gas as disappeared in the last experiment. b) lavoisier noticed that about four-fifths of the air had been used up. c) he noticed that there was a gas that did not support life or burning. d) a red oxide of mercury was formed on the surface of the mercury in the retort.

Why was the sample heated in step 5? describe the chemical principles involved in the reasoning behind this step?

Resperation is a way to release carbon back into the atmosphere

For the strategies below, decide whether they are best described as demand-side solutions or supply-side solutions to meeting human needs for fresh water. remember that a demand-side solution reduces demand for fresh water, whereas a supply-side solution increases the supply of fresh water. (a) damming a river to create a reservoir (b) desalinating seawater (c) a nation invading a neighboring country to access their rivers (d) raising water prices for consumers and businesses (e) providing tax breaks for companies that use less water (f) replacing inefficient irrigation with more-efficient drip irrigation to grow crops (g) requiring low-flow showerheads in all new homes