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Rust is a compound that occurs when the element iron and oxygen combine. Do they create a physical or a chemical change?

Which units can be used to measure length or distance? check all that apply. gram meter kilometer liter inch

Ammonia enters the expansion valve of a refrigeration system at a pressure of 10 bar and a temperature of 18oc and exits at 6.0 bar. the refrigerant undergoes a throttling process. determine the temperature, in oc, and the quality of the refrigerant at the exit of the expansion valve.

Need people build a dam to create a reservoir that supplies water a nearby city needs. describe two ways this action will likely affect the water cycle in the local environment. (5 points) worth 20 points