What is the mass of a sample of NH3 containing 6.3 x 1024 molecules of NH3? O 157 grams
O 178 grams
O 182 grams
198 grams

Two liquids are poured into a beaker. after a few seconds, the beaker becomes warm. which of the following best describes this reaction? a. an exothermic reaction b. a decomposition reaction c. an endothermic reaction d. a single-displacement reaction

Compare and contrast an assemblage and a pollen fingerprint by defying both and giving examples of each from the chapter.

How long could you survive without electricity? what parts of your life would be affected by loss of electricity? should you prepare for an electricity outage, and if so, how would you prepare? what backup system could your family or community install to generate limited amounts of electricity during an outage? how does this system create an electric force field and generate electric current?