4. When electromagnetic radiation (light) is produced it usually takes two steps. One will be an endogonic step (endogonic=endothermic) and another will be an exogonic (exogonic=exothermic). These steps are
what you described in both interpretations #1 and #2 above. You are to clearly describe which
step is the endogonic and which is the exogonic. Provide a brief explanation to back up your response.

Use the periodic table to determine the electron configuration of dysprosium (dy) and americium (am) in noble-gas notation.

15. which of the following is not human-caused groundwater pollution? a. water in an aquifer dissolves elements such as arsenic and mercury from surrounding rock. b. water in an aquifer is contaminated by leachate that seeps into the ground from a landfill. c. water in an aquifer becomes polluted with chemicals used in hydraulic fracturing, or fracking. d. water in an aquifer absorbs harmful bacteria from the drainage field of a septic tank.

Select the correct answer. wax is a nonpolar substance. in which type of substance is it the most soluble?