Question

Bohr model can explain: (a) The solar spectrum. (b) The spectrum of hydrogen molecule. (c) The spectrum of hydrogen atom only. (d) Spectrum of an atom or ion containing one electron only.

Short answer

The Bohr model can explain the spectrum of a hydrogen atom and any atom or ion with one electron.

Step-by-step solution

Understanding the Bohr Model

The Bohr model of the atom specifically describes the structure of a hydrogen atom. It is useful for atoms or ions that essentially have only one electron orbiting around a nucleus.

Analyzing each option

- Option (a): The solar spectrum includes many different elements, not just hydrogen or single-electron systems, so it cannot be explained by the Bohr model. - Option (b): The spectrum of a hydrogen molecule involves multiple hydrogen atoms; the Bohr model is not designed to explain molecular spectra. - Option (c): The Bohr model explains the hydrogen atom's spectrum effectively, as it deals with a single electron orbiting a nucleus. - Option (d): The Bohr model can also explain the spectrum of any single-electron system (such as ionized helium or lithium).

Finding the correct answer

Given the explanations above, the Bohr model is applicable in scenarios involving single-electron species. This means the correct answers would be options (c) and (d), as both fall under this category.

Key concepts

Hydrogen Atom Spectrum

The hydrogen atom spectrum is a beautiful yet foundational piece of atomic science. It represents the different wavelengths of light that a hydrogen atom can emit or absorb. When an electron in a hydrogen atom shifts between energy levels, it either absorbs or emits a photon of light. This dynamic process is the essence of the hydrogen spectrum.

One of the most famous series in the hydrogen spectrum is the Balmer series, which involves wavelengths in the visible range. It is this series that gives hydrogen its characteristic colors when observed through a spectroscope. There's also the Lyman series, observed in the ultraviolet range, and the Paschen series, which appears in the infrared.

• The shifting of electrons between orbits in the hydrogen atom leads to emission or absorption of specific light wavelengths.
• The spectrum is unique to hydrogen and acts like a fingerprint in analyzing celestial bodies.

These spectral lines can also help us understand other elements and give us insights into the universe, as hydrogen is the most abundant element in the cosmos.

Single-electron Systems

Single-electron systems refer to atoms or ions that have only one electron orbiting the nucleus. The Bohr model is perfect for describing these systems. Why? Because it focuses solely on the interaction between one electron and its nucleus. This simplicity allows precise calculations and visualization of these tiny entities.

Examples of single-electron systems include:

• Neutral hydrogen atoms (one proton, one electron)
• Ionized helium (a helium nucleus with one remaining electron)
• Ionized lithium, stripped to just one electron

Systems like these are excellent for understanding basic quantum principles, as they strip away interactions with additional electrons. Each has its spectral lines providing important information about their structure and behavior.

Atomic Spectra

Atomic spectra are like the unique barcodes of each element. When atoms absorb energy, their electrons jump to higher energy levels. Upon returning to a lower state, they emit light at specific wavelengths.

This emitted light creates a spectrum with distinct lines or colors. With the Bohr model, this is well explained for simple atoms like hydrogen or ions with a single electron.

Each line in an atomic spectrum corresponds to a transition between energy levels. These transitions help scientists determine the composition of distant stars and galaxies by comparing observed spectral lines with known ones from the atomic spectra of elements on Earth.

Atomic spectra have provided a clearer understanding of the atomic structure and the quantized nature of electronic transitions.

Quantum Theory

Quantum theory is the grand umbrella that explains the behavior of particles at small scales. It was a breakthrough in understanding phenomena that classical physics couldn't explain. Within this realm, the Bohr model of the atom emerged as a pivotal piece.

The Bohr model introduced key elements of quantum theory to atomic physics. It posited that electrons occupy "quantized" energy levels, meaning they can only exist at specific energies around a nucleus.

This idea of quantization stemmed from Planck's work on blackbody radiation and Einstein's work on the photoelectric effect. Later, Heisenberg, Schrödinger, and Dirac would expand these ideas into what's now known as quantum mechanics.

Quantum theory is crucial for modern technology and our understanding of atomic and subatomic realms. It explains everything from the behavior of semiconductors in electronics to nuclear reactions powering the sun.