Calculate the wavelength, in nanometers, of the light emitted by a hydrogen atom when its electron falls from the n = 7 to the n = 4 principal energy level. recall that the energy levels of the h atom are given by en = –2.18 × 10–18 j(1/n2)

The wavelength of the light emitted by a hydrogen atom for the given transition is 2166 nm.

Explanation:

The energy of nth energy levels of the H atom is given as:

Energy of the seventh energy level =

Energy of the seventh energy level =

Energy of the light emitted will be equal to the energy difference of the both levels.

Wavelength corresponding to energy E can be calculated by using Planck's equation:

The wavelength of the light emitted by a hydrogen atom for the given transition is 2166 nm.

we can conclude that the melting point of table salt is above room temperature (it's actually 801 deg c). the melting point of mercury must be below room temperature (- 39 deg c).

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