What happens to the length of sunlight during autumn and spring?

During the equinox, which happens in spring and fall, the earth tilts to give the equator the most direct sun. During the winter solstice, the Southern Hemisphere is tilted most toward the sun. The closer we get to Dec. 21, the shorter the days will get, but after that, the days will gradually get longer again.

Explanation:

The wavelength of the Balmer series spectral line corresponding to n = 12 is 375 nm.

Explanation:

let λ be the wavelrngth of the spectral line.

let ni be the initial energy state, for Balmer series, ni = 4.

let nf be the final energy level, n = 12.

Balmer series states the following:

1/λ = R[1/(ni)^2 - 1/(nf^2))

λ = 1/[R[1/(ni)^2 - 1/(nf^2))]

  = 1/[(1.09737×10^7)×[1/(4)^2 - 1/(12^2))]

  = 375 nm

Therefore, the wavelength of the Balmer series spectral line corresponding to n = 12 is 375 nm.