Which practice is harmful to the land?
a) using animal waste as fertilizer
b) composting with peels from commercial fruit
c) throwing paint cans in the garbage
d) cutting the lawn with a gas-powered mower

Achemical reaction (also known as a chemical change) produces substances that are chemically different from the starting materials. an example of a chemical reaction is the formation of water from hydrogen and oxygen gas.in a physical change, a substance changes its physical appearance but not its chemical identity. an example of physical change is the formation of liquid water from solid water, a familiar process called melting. physically, liquid water looks very different from solid water (ice) but the chemical identity, water, is the same for both. which of following changes that affect the composition of our atmosphere involve physical changes and which involve chemical reactions? oxygen gas changes to ozone during thunderstorms carbon dioxide is produced by the combustion of gasoline in an automobile engine. when coal, oil, and natural gas are decomposed in landsills they produce methane gas. freezing rain develops when a warm air mass overrides a cold air mass. fog forms from water vapor when the temperature drops below the dew point

At 300 mm hg, a gas has a volume of 380 l, what is the volume at standard pressure

What is the empirical formula of c6h18o3? ch3o c2h5o c2h6o c2h5o5