Atomic Spectra and X-rays
9.1 Atomic Spectra and X-rays
Learning Objectives
- Describe the absorption and emission of radiation in terms of atomic energy levels and energy differences
- Use quantum numbers to estimate the energy, frequency, and wavelength of photons produced by atomic transitions in multi-electron atoms
- Explain radiation concepts in the context of atomic fluorescence and X-rays
Practice!
| Practice 9.1.1 |
|---|
Let’s say we have He (not ionized) in the 1st excited state: How does the energy needed to remove this electron (n = 2) compare to the energy required to remove the n = 2 electron from He+?  |
| A. More energy is required |
| B. An equal amount of energy is required |
| C. Less energy is required |
X-Ray Tubes
Practice!
| Practice 9.1.2 |
|---|
| What is the principal quantum number of the final state of an atom as it emits an Mβ line in an x-ray spectrum? |
| A. 1 |
| B. 2 |
| C. 3 |
| D. 4 |
| E. 5 |
| Practice 9.1.3 |
|---|
| What is the principal quantum number of the initial state of an atom as it emits an Mβ line in an x-ray spectrum? |
| A. 1 |
| B. 2 |
| C. 3 |
| D. 4 |
| E. 5 |
Practice!
| Practice 9.1.4 |
|---|
| Characteristic x-rays can be produced by bombarding targets with electrons. These x-rays occur when |
| A. electrons from higher shells fill the vacant lower shell |
| B. electrons fill the vacant valence shell |
| C. photons are emitted with energies on the order of 103 eV |
| D. photons are emitted with wavelengths on the order of 103 nm |
| Practice 9.1.5 |
|---|
| In an x-ray tube, as you increase the energy of the electrons striking the metal target, do the wavelengths of the characteristic x-rays increase, decrease, or remain constant? |
| A. increase |
| B. decrease |
| C. remain constant |
Discuss!
Calculate the frequency (in Hz) of the photon produced when an electron of 20 keV is brought to rest in one collision with a heavy nucleus.
What is the wavelength of this photon?
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