Download How are quantum numbers used to describe electrons

How are quantum numbers used to describe electrons?
Name
Symbol
Possible Values
Description
for known
elements
Principal
The higher the energy level, the _____________the orbital,
quantum number
the longer the time the electron is _______________ from
(this tells which
the nucleus
The higher the energy level, the more ______________ the
electron has, the less it is bound by the nucleus
0 refers to s
2 refers to d
1 refers to p
3 refers to f
Angular
momentum
quantum number
(this tells which
0-3
Magnetic
quantum number
(this describes
the
Because an s orbital is _________________, it can have
only one orientation in space so m = 0 (this is why there is
only one orbital in s)
A p sublevel can be oriented about the 3 axes in space
_____ ways. This is why p has 3 orbitals.
ml
How many different ways can d orbitals be oriented about
the 3 axes in space?
Spin magnetic
quantum number
ms
+1/2 or -1/2
f orbitals?
Electrons in the same orbital must have _______________
spins
Each energy level can have n2 orbitals and 2n2 electrons. For instance, for the second energy level, n = 2 so it
has 22 orbitals (4 orbitals—1 s orbital and 3 p orbitals). It can hold 8 electrons.
How many orbitals in the 4th energy level?
How many electrons can be in the 4th energy level?
For the known elements, ________ orbitals and ______ electrons is the maximum number in energy levels 5-7.
What rules are used to explain how electrons fill orbitals?
Pauli exclusion principle—no two electrons in an atom can have the same set of four quantum numbers
If electrons are in the same orbital, they must have __________________spins so the fourth quantum
number is different. We illustrate this by drawing one arrow up and one arrow down.
Hund’s rule—for orbitals with the same energy (degenerate orbitals), the lowest energy is attained when the
number of electrons with the same spin is maximized.
When filling a sublevel, one electron must be placed in each orbital before they can be
paired; unpaired electrons have the same spin
This helps to minimize electron repulsion
What do we know about electrons if the first three quantum numbers are the same?