Hydrogen emits light with a wavelength of 656 nm. Find the frequency of this light

The density of a planet is 0.69 g/cm3 (density of water is 1.0 g/cm3). which of the following planets might this be? a. mercury b. venus c. saturn d. mars

Which describes interactions between substances and stomata during photosynthesis? check all that apply. oxygen enters stomata. oxygen is released through stomata. carbon dioxide enters stomata. carbon dioxide is released through stomata. hydrogen enters stomata. hydrogen is released through stomata.

Long term exposure to waves can cause sunburns and skin cancer. a) visible b) infrared c) gamma rays d) ultraviole