Students want to gather evidence for the claim that the number of atoms present before a chemical reaction is equal to the number of atoms present after the chemical reaction. They decide to react vinegar and baking soda in a sealed plastic bag. Which of the following would provide evidence the students need

Ageochemist examines a piece of metal that he found in the soil. he performs tests to identify the metal from its density, electrical conductivity, and melting point. which statement best describes his investigation? a. he is determining physical properties that are sufficient to identify the metal.b. he is determining chemical properties that are sufficient to identify the metal.c. he is determining physical properties that are insufficient to identify the metal.d. he is determining chemical properties that are insufficient to identify the metal.

What is the volume of 2.5 moles of nitrogen gas (n2)at standard temperature and pressure (stp)?

The reaction below shows a system in equilibrium. how would a decrease in temperature affect this reaction? a. the rate of formation of the gases would increase. b. the equilibrium of the reaction would shift to the left. c. the equilibrium would shift to cause the gases to sublime into solids. d. the chemicals on the left would quickly form the chemical on the right.