Studying the line spectra produced by hot gases and absorbed by cooler gases allows us to identify the elements in stars. When a gas is very hot, it doesn’t emit all wavelengths of light. Hot gases ...

The basic principles of AAS can be expressed as follows. Firstly, all atoms or ions can absorb light at specific, unique wavelengths. When a sample containing copper (Cu) and nickel (Ni), for example, ...

The Zeeman effect and optical pumping are two mechanisms capable of inducing polarization signals in the spectral lines that originate in the outer layers of stellar atmospheres. The Zeeman effect 12 ...

Atomic Absorption Spectroscopy (AAS) is a technique that deals with the absorption of electromagnetic radiation of free gaseous atoms at a specific wavelength. AAS allows the measurement of extremely ...

Transitions between different electronic energy levels in elements occur at unique energies and intensities, giving each element a distinctive emission spectrum. When the energy of an incident photon ...

Plasmon-enhanced molecular spectroscopies have attracted tremendous attention as powerful detection tools with ultrahigh sensitivity down to the single-molecule level. The optical response of ...