Chemistry Chapter 7
Terms in this set (45)
a periodic back and forth motion that tranmits energy
the high points of a series of waves
the low points of a series of waves
the distance between any two corresponding points on successive waves
considered the measure of the the waves strength
the number of comploete waves (crests plus troughs)
that pass by a point in a given time
the SI unit of frequency
simply the rate at which a wave travels
praticle theroy of light
the idea that light can be pitured as treams of tiny particles emmitted by light sources
wave theory of light
states that light consists of a series of waves rather than indivisual particles
an electric vibrating field and a magnetic vibrating field that act together as a single wave
an arrnagement of all forms of electromagnetic radiation in order of freque4ncy and wavelength
seven broad categories of the electromagntic spectrum
radio waves, microwaves, infrared waves, visible light, ultraviolet waves, x-rays, and gamma rays.
wave particle duality
the two-sided nature of light (wavelike when dealing with transmission and particlelike when dealing with matter)
quantum theory of light
light consists of tiny bundles or "pakets" of energy called photons
electromagnetic waves travelin as photons
an instrument used to separate the colors by frequency
a spectrum containing only certain colors
a spectrum containing a complete array of colors
the fixed amount of energy that a system described by quantum mechanics, such as a molecule, atom, electron, or nucleus, can have.
the lowest energy state of an atom or other particle.
In quantum mechanics, an excited state of a system (such as an atom, molecule or nucleus) is any quantum state of the system that has a higher energy than the ground state (that is, more energy than the absolute minimum).
are a central part of the theory of quantum mechanics, being an example of wave-particle duality. The concept that matter behaves like a wave is also referred to as the de Broglie hypothesis (/dəˈbrɔɪ/) due to having been proposed by Louis de Broglie in 1924.
Because electrons behave as waves, they can be used to "illuminate" objects in a manner similar to light. An electron microscope is an instrument that takes advantage of this situation. Electrons are given energy by accelerating them in a manner similar to the way a TV tube works. Then, using magnetic fields, they are directed at an object of interest. The electrons are focused to illuminate the object, and then to form the image of that object. A schematic diagram is shown in the diagram. This system can be used to look closely at very small objects.
The atom is mostly space with a small, very dense, centrally located nucleus that contains positively charged protons and neutrally charged neutrons and is surrounded by negatively charged electrons located in orbitals in the electron cloud.
a vibration of a system in which some particular points remain fixed while others between them vibrate with the maximum amplitude.
any of a variety of mathematical inequalities asserting a fundamental limit to the precision with which certain pairs of physical properties of a particle, known as complementary variables, such as position x and momentum p, can be known.
regions of space in which there is a high probability of finding eletrons
is a definite path in space; used in the Bohr model
electron cloud models
an informal term in physics. It is used to describe where electrons are when they go around the nucleus of an atom
detmines how the atom chemcially bonds to other atoms and influences the shape of its orbital in space (vertically, horizontally, or diagonally positioned) and its spin (either clockwise or counterclockwise).
principle quantum number
the first quantum numberand describes the the electron shell or main energy level of teh electron; it may have any positive integral value n=1, 2, 3...
What happens when the value of n becomes larger?
1. the energy of an electon in that shell becomes larger
2. the eletron's most probable distance from the nucleus becomes larger;
3. the number of electrons possible increase; and
4. the size of teh electron cloud increases.
how orbitals within a shell are divided; have the same value of the angular quantum number (l); are indicative of the shape of the the electon's orbital.
How do chemist describe the shell and subshell in which an orbital belongs?
with a two-character code such as 2p or 4f.
s orbital shape
p orbital shape
d orbital shape
magnetic quantum number
The quantum number corresponding to the shape of electron subshells in an atom. Also called third quantum number; describes the orientation in space with respect to the x,y and z axis.
spin quantum number
described as the fourth quantum number; two possible spin directions (clockwise and counterclockwise) which must be opposite when two electrons occupy an orbital
Pauli exclusion principle
The principle that two fermions of a given type, such as electrons, protons, or neutrons, cannot occupy the same quantum state. It does not apply to bosons. This principle plays a key role in the electron orbital structure of atoms, since it prevents more than two electrons from occupying any given orbital (two are allowed, since they may have opposite spin, and thus be in different quantum states).
states that, hypothetically, electrons orbiting one or more atoms fill the lowest available energy levels before filling higher levels (e.g., 1s before 2s). In this way, the electrons of an atom, molecule, or ion harmonize into the most stable electron configuration possible.
every orbital in a subshell is singly occupied with one electron before any one orbital is doubly occupied, and all electrons in singly occupied orbitals have the same spin.
an electron that is associated with an atom, and that can participate in the formation of a chemical bond;
Lewis symbol or diagram
depicts a molecule using an element symbol to represent the nucleus and core electrons of each atom. Valence electrons are represented by lines for electron pair bonds and dots for unbonded electrons.