hydrogen-like

(adjective)

having a single electron

Related Terms

Examples of hydrogen-like in the following topics:

  • Energy of a Bohr Orbit

    • So, if a nucleus has $Z$ protons ($Z=1$ for hydrogen, $Z=2$ for helium, etc.) and only one electron, that atom is called a hydrogen-like atom.
    • The spectra of hydrogen-like ions are similar to hydrogen, but shifted to higher energy by the greater attractive force between the electron and nucleus.
    • Using this equation, the energy of a photon emitted by a hydrogen atom is given by the difference of two hydrogen energy levels:
    • Bohr's model predicted experimental hydrogen spectrum extremely well.
    • Apply proper equation to calculate energy levels and the energy of an emitted photon for a hydrogen-like atom

  • Problems

    • Derive the lifetime of the $n=2, l=1, m=0$ state of hydrogen to emit a photon and end up in the $n=1, l=0, m=0$ state.
    • Consider that the mass fraction of the different atoms are hydrogen (0.7), helium (0.27), carbon (0.008), oxygen (0.016) and iron (0.004).

  • Multielectron Atoms

    • Hydrogen is the only atom in the periodic table that has one electron in the orbitals under ground state.
    • In hydrogen-like atoms (those with only one electron), the net force on the electron is just as large as the electric attraction from the nucleus.

  • Basic Assumptions of the Bohr Model

    • Bohr explained hydrogen's spectrum successfully by adopting a quantization condition and by introducing the Planck constant in his model.
    • Here, Bohr explained the atomic hydrogen spectrum successfully for the first time by adopting a quantization condition and by introducing the Planck constant in his atomic model.
    • The Rutherford–Bohr model of the hydrogen atom ($Z= 1$) or a hydrogen-like ion ($Z>1$), where the negatively charged electron confined to an atomic shell encircles a small, positively charged atomic nucleus, and where an electron jump between orbits is accompanied by an emitted or absorbed amount of electromagnetic energy ($h\nu$).
    • The $3 \rightarrow 2$ transition depicted here produces the first line of the Balmer series, and for hydrogen ($Z= 1$) it results in a photon of wavelength 656 nm (red light).

  • de Broglie and the Bohr Model

    • The wave-like properties of matter were subsequently confirmed by observations of electron interference when scattered from crystals.
    • When an electron is bound to an atom, its wavelength must fit into a small space, something like a standing wave on a string.
    • This described electrons that were constrained to move about the nucleus of a hydrogen-like atom by being trapped by the potential of the positive nuclear charge.
    • I include a summary of the hydrogen atom's electronic structure and explain how an electron can interfere with itself in an orbit just like it can in a double-slit experiment.

  • Quantum-Mechanical View of Atoms

    • Hydrogen-1 (one proton + one electron) is the simplest form of atoms, and not surprisingly, our quantum mechanical understanding of atoms evolved with the understanding of this species.
    • Bohr's model successfully explained spectroscopic data of hydrogen very well, but it adopted a semiclassical approach where electron was still considered a (classical) particle.
    • Thereafter, the planetary model of the atom was discarded in favor of one that described atomic orbital zones around the nucleus where a given electron is most likely to be observed.
    • Modern quantum mechanical view of hydrogen has evolved further after Schrödinger, by taking relativistic correction terms into account.
    • One of the hydrogen's atomic transitions (n=2 to n=1, n: principal quantum number) has been measured to an extraordinary precision of 1 part in a hundred trillion.

  • Nuclear Fusion

    • The sun is a main-sequence star and therefore generates its energy through nuclear fusion of hydrogen nuclei into helium.
    • In its core, the sun fuses 620 million metric tons of hydrogen each second.
    • For example, in the fusion of two hydrogen nuclei to form helium, 0.7 percent of the mass is carried away from the system in the form of kinetic energy or other forms of energy (such as electromagnetic radiation).
    • It takes considerable energy to force nuclei to fuse, even nuclei of the lightest element, hydrogen.
    • This is because all nuclei have a positive charge due to their protons, and since like charges repel, nuclei strongly resist being put close together.

  • Hydrogen Spectra

    • The observed hydrogen-spectrum wavelengths can be calculated using the following formula: $\frac{1}{\lambda} = R(\frac{1}{n_f ^2} - \frac{1}{n_i ^2})$.
    • Maxwell and others had realized that there must be a connection between the spectrum of an atom and its structure, something like the resonant frequencies of musical instruments.
    • As you might expect, the simplest atom—hydrogen, with its single electron—has a relatively simple spectrum.
    • The hydrogen spectrum had been observed in the infrared (IR), visible, and ultraviolet (UV), and several series of spectral lines had been observed .
    • The observed hydrogen-spectrum wavelengths can be calculated using the following formula:

  • Biology: DNA Structure and Replication

    • Hydrogen bonding, brought on by electrostatic interactions, is critical to holding together strands of DNA.
    • Electrostatic interactions, in this case otherwise known as hydrogen bonds, are what hold these bonds together.
    • For adenine and thymine, there are two such hydrogen bonds.
    • These enzymes break the electrostatic hydrogen bonds between the two strands.
    • Describe effect of the DNA replication process on the hydrogen bonds

  • Spherical Distribution of Charge

    • Through the work of scientists in the late 18th century, the main features of the electrostatic force—the existence of two types of charge, the observation that like charges repel, unlike charges attract, and the decrease of force with distance—were eventually refined, and expressed as a mathematical formula.
    • The charge distribution of the oxygen molecule is negative, and attracts the two positive hydrogen molecules.
    • It is a polar molecule because there is still a permanent charge separation because the electrons spend more time near the oxygen than the hydrogens.
    • The electrons spend more time near the oxygen than the hydrogens, giving a permanent charge separation as shown.