Grace injured her ankle while running a relay race at the family reunion. Her aunt breaks the inner, activator portion of an instant cold pack releasing the solid urea into the surrounding water. How could Grace modify this device to make it colder faster? A) Expand the volume of the urea in the activator cell. B) Maximize the overall size and volume of the cold pack. Eliminate C) Increase the concentration both main and activator phases. D) Include a slow release activator solution to increase longevity.

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

What is the relationship of air masses and the temperature of oceans?

Express the following number in scientific notation. 0.026890 =