Which of these can be classified as a pure substance a. solution b. heterogeneous mixture c. compound d. homogeneous mixture

Which type of bond is present in hydrogen sulfide (h2s)? the table of electronegativities is given. a. hydrogen b. ionic c. nonpolar covalent d. polar covalent

Analyze the reaction to determine whether the reaction is exothermic or endothermic. explain your reasoning.

How is electrolysis most commonly used to produce an energy source? a - splitting water molecules produces oxygen, which organisms breathe to fuel their bodies. b - splitting water molecules produces hydrogen gas, which is used to power machines through hydrogen fuel cells. c - splitting carbon dioxide molecules produces coal, a form of carbon that can be burned to produce heat. d - splitting carbon dioxide molecules produces natural gas, which can be burned to generate electricity in power plants.