How does an electron emit light?

Which formula can be used to calculate the molar mass of hydrogen peroxide

One way that radioactive waste is treated is by burying it in repositories. the repositories are found only in states with very low populations. true or false? a. trueb. false(also i meant to put high school but it put down middle school instead)

Ahydrogen atom has 1 electron. how many bonds can hydrogen form? a) 1 b) 2 c) 3 d) 4 e) 5