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Ch. 4 Vocabulary
How Atoms are Arranged
| Question | Answer |
|---|---|
| Electromagnetic radiation | A form of energy that exhibits wavelike behavior as it travels through space. |
| Electromagnetic spectrum | All the forms of electromagnetic radiation. |
| Wavelength | The distance between corresponding points on adjacent waves. |
| Frequency | The number of waves that pass a given point in a specific time, usually one second. |
| Visible Light | A kind of electromagnetic radiation. |
| Velocity of a wave | 3.0 x 108 m/s |
| Photoelectric effect | The emission of electrons from a metal when light shines on the metal. |
| Quantum | The minimum quantity of energy that can be gained or lost by an atom. |
| Planck’s Constant | In the equation E = hv, h is the fundamental physical constant known as Planck’s Constant: h = 6.626 x 10-34 (J)(s). |
| Photon | A particle of electromagnetic radiation that has zero rest mass and carries a quantum of energy. |
| Energy of a Photon | Depends on the frequency of the radiation: Ephoton = hv. |
| Ground State | The lowest energy state of an atom. |
| Excited State | A state in which an atom has a higher potential energy that it has in its ground state. |
| Line-emission spectrum | A series of specific wavelengths of emitted light created when the visible portion of light from excited atoms is shined through a prism. |
| Continuous spectrum | The emission of a continuous range of frequencies of electromagnetic radiation. |
| Bohr radius | An electron can circle the nucleus only in allowed paths, or orbits. |
| Interference | Occurs when waves overlap.This overlapping results in a reduction of energy in some areas and an increase of energy in others. |
| Heisenberg Uncertainty Principle | It is impossible to determine simultaneously both the position and velocity of an electron of any other particle. |
| Quantum Theory/Quantum Mechanics | A mathematical description of the wave properties of electrons and other very small particles. |
| Orbital | A three-dimensional region around the nucleus that indicates the probable location of an electron. |
| Quantum numbers | Numbers that specify the properties of atomic orbitals an the properties of electrons in orbitals. |
| Principle Quantum number (n) | The quantum number that indicates the main energy level occupied by the electron. |
| Angular momentum quantum number (l ) | The quantum number that indicates the shape of the orbital. |
| Magnetic quantum number (m) | The quantum number that indicates the orientation of an orbital around the nucleus. |
| Spin quantum number (s) | The quantum number that has only two possible values, +1/2 and -1/2, which indicate the two fundamental spin states of an electron in an orbital. |
| Aufbau Principle | An electron occupies the lowest-energy orbital that can receive it. |
| Electron Configuration | The arrangement of electrons in an atom. |
| Pauli Exclusion Principle | No two electrons in the same atom can have the same set of four quantum numbers. |
| Hund’s Rule | Orbitals of equal energy are each occupied by one electron before any orbital is occupied by a second electron, and all electrons in singly occupied orbitals must have the same spin. |
| Valence Electron | An electron that is available to be lost, gained, or shared in the formation of chemical compounds. |
| Inner-shell electrons | Electrons that are not in the highest occupied energy level. |
| Highest occupied energy level | The electron-containing main energy level with the highest principal quantum number. |
| Noble Gas Configuration | An outer main energy level fully occupied, in most cases, by eight electrons. |
| s sublevel or sub-orbital | Orbital with lowest energy. In a ground-state hydrogen atom, the electron is in this orbital. |
| p sublevel or sub-orbital | Orbital with the next highest energy. |
| f sublevel or sub-orbital | Orbital with highest energy level. |