When an excited electron in a hydrogen atom falls from =5 to =2, a photon of blue light is emitted. if an excited electron in an he+ ion falls from =4, which energy level must it fall to ) for blue light of a similar wavelength to be emitted?

The human activities in two locations are described below: location a: rampant use of plastic containers location b: excessive use of pesticides and fertilizers which statement is most likely true? location a will have poor air quality because plastic is biodegradable. location a will experience water scarcity because plastic absorbs moisture. the population of honeybees will increase in location b because production of crops will increase. the population of fish in location b will decrease because the water is contaminated.

Why is the bottom layer of a trophic pyrimid the

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