For helium, let’s label the emission wavelengths, λ(nf, ni) where nf and ni are, respectively, the principal quantum numbers of the final and the initial states. Calculate the following emission wavelengths: λ(3,4), λ(4,6), λ(4,7) λ(4,8) and λ(4,9).

Explanation:

Using Rydberg equation

where;

R is Rydberg equation = 1.097 x 10⁷ m⁻¹

For λ(3,4)

For λ(4,6)

For λ(4,7)

For  λ(4,8)

For  λ(4,9)

magnified images possible images can be real = projected onto a screen

it is given that trillions of microbes make up to 1% to 3% of the body mass.

let's take average of this percentage: 2%

consider the average mass of the human body as 70 kg.

then, trillions of microbes would have mass  

therefore, 100 trillion micro-organisms would weigh:

this is an approximate value and could change depending on the mass of the human body and percentage of the microbes present in it.

average mass per microorganism =