Two members of the Boron family owe their names to bright lines in their emission spectra. Indium has a bright indigo blue line (451.1nm) and Thallium has a bright green line (535.0 nm). What are the energies of these two spectra lines?

Does anyone know a lot about how to: - calculate mass of magnesium metal - calculate the actual yield of magnesium oxide - calculate the theoretical yield of mgo - calculate the percent yield of mgo - determine the percent yield of mgo - determine the average percent yield of mgo i had to do an online lab and its asking these questions but i have no idea where to start or how to be able to find these things. i can post the chart of the data from the lab or if you can tell me exactly how i can find each.

Which element has the lowest electronegativity? calcium(ca) gallium(ga) selenium(se) bromine(br)

Which of the following has wavelength longer than the wavelength of viable light? a) x rays b) gamma rays c) radios waves d) ultraviolet waves