Calculate the frequency of thę light absorbed by a hydrogen atom during a transition of its electron from the n = 1 to the n =
3 principal energy level. Recall that for hydrogen En = -2.18 x
10-18 J(1/12) and (n = 6.63 x 10-34 Jo s).

the major pests we deal with are insects, weeds and fungal diseases. a pesticide is a product, whether organic or chemical, used to kill the target pest. there are other techniques gardeners should use that can prevent the severe infestations that make the use of pesticides necessary

nuclear fission produces elements that are heavier than helium.

the elements that are used in nuclear fission and their products are much heavier than helium.