Download Chapter 5 Electrons In Atoms 5.1 Models of the Atom The

Chapter 5 Electrons In Atoms
5.1 Models of the Atom
The Development of Atomic Models
The model for the atom consisted of protons and neutrons making up a nucleus
surrounded by electrons.
The Bohr Model
Bohr proposed that an ______________ is found only in specific circular paths, or
orbits, around the nucleus.
The fixed energies an electron can have are called __________________ levels.
The fixed energy levels of electrons are somewhat like the rungs of the ladder .
A ___________________ of energy is the amount of energy required to move an
electron from one energy level to another energy level.
The Quantum Mechanical Model
The quantum mechanical model determines the allowed energies an
_____________ can have and how likely it is to find the electron in various
locations around the nucleus.
The quantum mechanical model description of how the ___________________
moving around the nucleus is similar to the motion of a rotating propeller blade.
Atomic Orbitals
An _______________________ orbital is often thought of as a region of space in
which there is a high probability of finding an electron.
The energy levels of _____________________________ in the quantum
mechanical model are labeled by principal quantum numbers (n). These are
assigned the values n=1, 2, 3, 4 and so forth.
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Each energy sublevel corresponds to an orbital of a different shape, which describes where the
_____________________ is likely to be found.
Four of the five kinds of d orbitals have clover leaf shapes.
The lowest principal energy level (n=1) has only one sublevel, called___________
The number of electron allowed in each of the first four energy levels is shown in table 5.2
5.2 Electron Arrangement in Atoms
Electron Configurations
The ways in which ___________________ are arranged in various orbitals around the nuclei of
atoms are called electron configurations.
Three rules - the aufbau principle, the Pauli exclusion principle, and Hund's rule - tell you how
to find the electron configuration of atoms.
According to the _____________ principle, electrons occupy the orbitals of lowest energy first.
According to the ______________ exclusion principle, an atomic orbital may describe at most
two electrons.
______________ rule states that electrons occupy orbitals of the same energy in a way that
makes the number of electrons with the same spin direction as large as possible.
Exceptional Electron Configurations
Copper has an ____________________ configuration that is an exception to the aufbau
principle. You can obtain correct electron configurations for the elements up to vanadium.
Some actual electron configurations differ from those assigned using the _____________
principle because half-filled sublevels are not as stable as filled sublevels, but they are more
stable than other configurations.
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