Question

Why does the emission spectrum for nitrogen reveal many more spectral lines than that for hydrogen?

Short answer

Nitrogen has a more complex electronic structure than hydrogen, resulting in more possible electron transitions and thus more spectral lines.

Step-by-step solution

Title - Understand What an Emission Spectrum Is

An emission spectrum is a spectrum of the electromagnetic radiation emitted by a source. When an atom or molecule absorbs energy, electrons get excited to higher energy levels. As they return to their lower energy levels, they emit photons of specific wavelengths, which form the emission spectrum.

Title - Review Hydrogen's Atomic Structure

Hydrogen is the simplest atom, having only one electron and one proton. Because there is only one electron, there are relatively few possible transitions between energy levels. These transitions generate fewer spectral lines in the emission spectrum.

Title - Analyze Nitrogen's Atomic Structure

A nitrogen atom is more complex, with seven electrons and seven protons. The presence of multiple electrons allows for a larger number of possible energy level transitions. Each unique transition corresponds to a different spectral line in the emission spectrum.

Title - Compare the Complexities of Both Elements

Compared to hydrogen, nitrogen has a more complex electronic structure. The additional electrons in nitrogen create more energy levels and potential transitions, leading to a richer and more diversified emission spectrum.

Title - Draw a Conclusion

The emission spectrum for nitrogen reveals many more spectral lines than that for hydrogen due to its more complex electronic structure, which allows for a greater number of possible electron transitions.

Key concepts

atomic structure

Atoms are the building blocks of all matter. Each atom consists of a nucleus, containing protons and neutrons, surrounded by electrons that orbit in various energy levels. These electrons can move between energy levels by absorbing or emitting energy. The simplest and smallest atom is hydrogen, which has only one proton and one electron. In contrast, a nitrogen atom is more complex with seven protons and seven electrons. The number of protons in an atom's nucleus is known as its atomic number and determines the element's identity. The different energy levels where electrons can reside are called shells or orbitals. The arrangement and interactions of electrons within these orbitals define an atom's electronic structure. This structure plays a crucial role in determining the atom's chemical properties and the nature of its emission spectrum.

electron transitions

Electron transitions occur when an electron moves from one energy level to another within an atom. These movements happen because electrons absorb or emit specific amounts of energy. When an electron absorbs energy, it gets excited and jumps to a higher energy level, which is called an excited state. Eventually, the electron will return to a lower energy level, emitting the absorbed energy in the form of a photon. The energy of this photon corresponds to a specific wavelength of light, which contributes to the emission spectrum of the element. In hydrogen, with only one electron, there are fewer possible transitions. Nitrogen, however, with its seven electrons, has many more potential transitions, each corresponding to a distinct spectral line. Therefore, the emission spectrum of nitrogen is more complex, displaying more spectral lines.

spectral lines

Spectral lines are the distinct lines that appear on an emission or absorption spectrum. These lines represent the wavelengths of light emitted or absorbed by electrons transitioning between energy levels within an atom. In an emission spectrum, lines are displayed when an electron drops to a lower energy level and emits a photon. Conversely, an absorption spectrum shows dark lines where light is absorbed to excite electrons to higher energy levels. Each element has a unique set of spectral lines, acting like a fingerprint that can be used to identify the element. For hydrogen, the spectral lines are fewer and simpler because it has just one electron with limited transitions. Nitrogen's multiple electrons and numerous energy levels result in a more detailed emission spectrum with many spectral lines. This diversity of lines helps scientists understand the atomic structure and behavior of different elements.