Spectroscopy and Spectral Lines

• In this lab, spectra of various elements using a spectroscope will be investigated.
• A spectroscope separates incoming light into constituent wavelengths.
• It allows for the observation of spectral lines characteristic of each element.

Theory of Spectral Lines

• Each element has a unique set of spectral lines, acting as a "fingerprint."
• Spectral lines arise from electron transitions between different energy levels within an atom.
• When an electron jumps from a higher energy level to a lower one, it emits a photon.
• $E = hf = \frac{hc}{\lambda}$ is the formula to work out the energy, frequency and wavelength.
• $E$ stands for the energy of the photon
• $h$ is Planck's constant, which is $6.626 \times 10^{-34} \text{ J s}$
• $f$ is the frequency of the photon
• $c$ is the speed of light, which is $3.0 \times 10^8 \text{ m/s}$
• $\lambda$ stands for the wavelength of the photon
• Measuring the wavelengths of spectral lines can identify elements present in a sample.

Spectroscope Procedure

• Set up the spectroscope with a light source to obtain a clear spectrum.
• Observe known elements like hydrogen, helium, and mercury, recording wavelengths of spectral lines.
• Observe unknown samples and compare spectral lines to known elements to identify the elements present.
• Calibrate the spectroscope using known spectral lines to improve the accuracy of wavelength measurements.
• Analyze the data to determine the composition of the unknown samples.

Data Table Information

• Hydrogen has spectral lines at 656 nm (Red), 486 nm (Blue-Green), and 434 nm (Violet).
• Helium has spectral lines at 588 nm (Yellow) and 501 nm (Green).
• Mercury has spectral lines at 579 nm (Yellow) and 546 nm (Green).
• There are spaces to record data for unknown samples 1 and 2.

Questions to Consider

• What is the relationship between the color of a spectral line and its wavelength?
• How can spectral lines be used to identify elements in a sample?
• What are some applications of spectroscopy in science and technology?

Conclusion of Spectroscope Lab

• The goal is to learn about element spectra using a spectroscope.
• Understand the relationship between spectral lines and atomic structure.