a hydrogen electron returns from energy level n=3 to n=1 what will the spectral lines emitted by this electron look like under a spectroscope

Which of the following explains why it took so long for the public to accept the negative health effects of smoking? a)people were waiting for counter reasons, and those were presented.b)scientists had not completely finalized their results, which took 30 years.c)cigarettes were cheaply available and media channels were very inefficient.d)cigarette manufacturers were trying hard to bring an alternative into the market

An architect plans to use solar energy to heat the next house he designs. what principle of absorption and infrared energy can be applied to the design of the new house? how could she apply to those principals?

Acertain radio station broadcasts radio waves that have a wavelength of 298cm what is its broadcast frequency?