When a low-pressure gas of hydrogen atoms is placed in a tube and a large voltage is applied to the end of the tube, the atoms will emit electromagnetic radiation and visible light can be observed. If this light passes through a diffraction grating, the resulting spectrum appears as a pattern of four isolated, sharp parallel lines, called spectral lines. Each spectral line corresponds to one specific wavelength that is present in the light emitted by the source. Such a discrete spectrum is referred to as a line spectrum. What is the wavelength of the line corresponding to n =4 in the Balmer series? Express your answer in nanometers to three significant figures. EVO AV Om ? X (n) = 4.86.10? By the early 19th century, it was found that discrete spectra were produced by every chemical element in its gaseous slale. Even though these spectra were found to share the common feature of appearing as a set of isolated lines, it was observed that each element produces its own unique pattern of lines. This indicated that the light emitted by each element contains a specific set of wavelengths that is characteristic of that element. Submit Previous Answers Request Answer X Incorrect; Try Again; 19 attempts remaining

a)   λ = 4.862 10⁻⁷ m,  b)  λ = 4.341 10⁻⁷ m

Explanation:

The spectrum of hydrogen can be described by the expression

in the case of the initial state n = 2 this series is the Balmer series

a) Find the wavelength for n = 4

let's calculate

          = 1,097 10⁷ ()

         \frac{1}{ \lambda} = 1.097 10⁷ 0.1875 = 0.2056 10⁷

          λ = 4.862 10⁻⁷ m

b) n = 5

    \frac{1}{ \lambda} = 1,097 10⁷ ()

    \frac{1}{ \lambda} = 1.097 10⁷ 0.21 = 0.23037 10⁷

     λ = 4.341 10⁻⁷ m

electromagnetic shielding is the practice of reducing the electromagnetic field in a space by blocking the field with barriers made of conductive or magnetic materials. shielding is typically applied to enclosures to isolate electrical devices from their surroundings, and to cables to isolate wires from the environment through which the cable runs. electromagnetic shielding that blocks radio frequency electromagnetic radiation is also known as rf shielding.

the shielding can reduce the coupling of radio waves, electromagnetic fields and electrostatic fields. a conductive enclosure used to block electrostatic fields is also known as a faraday cage. the amount of reduction depends very much upon the material used, its thickness, the size of the shielded volume and the frequency of the fields of interest and the size, shape and orientation of apertures in a shield to an incident electromagnetic

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fossil fuels burn

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human population grows worldwide