Section 7.3- Quantum Numbers and Electron Configuration Flashcards
drawn as 3D around the region that includes 90% of the dots
probability contour
the compete arrangement of electron in an atom is the atom’s
electron configuration
the Schrodinger equations allow scientists to describe any electron in an atom using four
quantum numbers
the four quantum numbers describe the
- electron’s shell or energy level
- the shape of its orbital
- the orientation of its orbital in space
- its spin
the first quantum number is known as the
principle quantum number (n)
the principle quantum number describes the
electron shell (main energy level)
the maximum number of electrons in an electron shell is
2n(squared)
in general, as the value of n becomes larger, so do the following
- the energy of an electron in that shell
- the electron’s most probable distance from the nucleus
- the number of electrons possible
- the size of the electron cloud
each shell is made up of closely grouped
subshells
the second quantum number indicated the shape or type of subshell in which an electron is found and is therefore called the
subshell quantum number (l)
determines SHAPE of orbital
SUBSHELL
possible subshell shapes
s= spheres
p = dumbbells
d= clover leaves
f= double clover leaves
in atoms with two or more electrons, the energy of each electron also depends on
l (subshell quantum number)
the number of orbitals is limited to the
energy level
the number of possible subshells in a particular shell equals the
principle quantum number
the third quantum number needed to describe an electron is the
magnetic quantum number (ml)
the magnetic quantum number describes the _______________________ of an individual orbital within a subshell
orientation in space
the city, street, and house number are all necessary to locate where a person lives, just as ___ _________ and ______ are necessary to describe the orbital of an electron
n
l
m
each orbital is occupied by a maximum of ___________ electrons
two
the spin of an electron is described by the fourth quantum number
spin quantum number (ms)
since there are two possible directions of spin - counterclockwise and clockwise- there are two value for ms:
positive 1/2
negative 1/2
two electrons in any given orbital must have opposite spins and thus opposite values for the spin quantum number making such electrons
paired
states that no two electrons in an atom may have the same set of four quantum numbers
Pauli exclusion principle
rule that states that electrons occupy the lowest-energy orbital available, filling in orbitals of successively higher energies until all the electrons are distributed
aufbau principle
rule that states that when a p, d, or f subshell is being filled, one electron will occupy each orbital in that subshell before pairing begins
Hund’s rule
only ___________ electrons can occupy one orbital
two
in the electron configurations of neutral atoms in their ground state, there are the same number of ___________ and _________________________
protons and electrons
maximum number of subshells a shell can have
the same number of subshells as corresponding energy level
(level 1- s
level 2- s p
level 3- s p d
level 4- s p d f )
the outermost electrons are the
valence electrons
there can be a maximum of ____________ valence electrons
8
it is often simpler and more instructive to represent these outer-energy-level electrons as dots written around the symbol for the element; such a symbol is known as a
Lewis symbol or electron-dot formula
the maximum amount of electrons that exist in an orbital
two
the maximum amount of electrons that exist in a energy level
2n squared
the maximum amount of electrons that exist in a subshell
number of orientations x 2
make the assumption that all inner elements have _____________ valence electrons
two
the use of all the quantum numbers together to give us the arrangement of all the electrons in an atom
electron configuration
use to represent the outermost shell of an electron
Lewis symbol
