Lithium (L) Sodium (Na) Potassium (K) 1 Calcium (Ca) Strontium (Sr) Barium (Ba)

Question

Lithium (L) Sodium (Na) Potassium (K) 1 Calcium (Ca) Strontium (Sr) Barium (Ba) Hydrogen (H) Helium (He) Neon (Ne) Argon (Ar) Figure 6 Line spectra of various elements. Reflection Questions The spectral lines observed for hydrogen arise from transitions from excited states back to the n 2 principal quantum level. Calculate the wavelengths associated with the spectral transitions of the hydrogen atom from the n = 6-5, 4, and 3 levels to the n-2 level. I. Suppose you use a diffraction grating that contains 600 lines mm-1 in your spectroscope. What effect would you expect this to have on the sharpness and resolution of the lines in your line spectrum? o start ac chemistry students. How could you ensure that all the spectroscopes created the same calibration line and equation? What would you need to be sure was always the same? What could be changed without affecting the calibration?

Explanation / Answer

1)

Apply Rydberg Formula

E = R*(1/nf^2 – 1/ni ^2)

R = -2.178*10^-18 J

Nf = final stage/level

Ni = initial stage/level

E = Energy per unit (i.e. J/photon)

For ni = 6

E = (-2.178*10^-18)*(1/6^2 – 1/2^2)

E = 4.84*10^-19 J

For ni = 5

E = (-2.178*10^-18)*(1/5^2 – 1/2^2)

E = 4.5738*10^-19 J

For ni = 4

E = (-2.178*10^-18)*(1/4^2 – 1/2^2)

E = 4.08375*10^-19

For ni = 3

E = (-2.178*10^-18)*(1/3^2 – 1/2^2)

E = 3.025*10^-19 J

For the wavelength:

WL = h c / E

h = Planck Constant = 6.626*10^-34 J s

c = speed of particle (i.e. light) = 3*10^8 m/s

E = energy per particle J/photon

WL = (6.626*10^-34)(3*10^8)/(E)

n = 6; E = 4.84*10^-19 J

WL = (6.626*10^-34)(3*10^8)/(4.84*10^-19) = 4.10702*10^-7 m = 410 nm

n = 5; E = 4.5738*10^-19 J

WL = (6.626*10^-34)(3*10^8)/(4.5738*10^-19) = 4.34605*10^-7 m = 434 nm

n = 4; E = 4.08375*10^-19

WL = (6.626*10^-34)(3*10^8)/(4.08375*10^-19) = 4.8675*10^-7 m = 486 nm

n = 3; E = 3.025*10^-19 J

WL = (6.626*10^-34)(3*10^8)/(3.025*10^-19) = 6.571*10^-7 m = 657 nm

NOTE:

Please consider posting all other questions in another set of Q&A. We are a not allowed to answer to multilpe questions in a single set of Q&A

Related Questions

Navigate

• Browse (All)
• Browse L
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.