Chapter 9 Periodic Properties of the Elements Flashcards
Necessary for the rapid electrical signaling in these cells
ion channels
Establish and control a voltage gradient in neurons
ion channels
properties whose values can be predicted based on the element’s position on the periodic table.
periodic properties
what is medeleev known for?
look at notes
when the elements are
arranged in order of increasing atomic
mass, certain sets of properties recur
periodically.
periodic law
allows us to predict
the properties of an element based on its
position on the table.
Mendeleev’s Periodic Law
what doesn’t Mendeleev’s Periodic Law explain?
why the pattern exists.
is a theory that explains
why the periodic trends in the properties exist.
Quantum mechanics
the location of electrons in atoms
electron configurations.
A description of the orbitals occupied by electrons is called
an
electron configuration.
which gives similar information but symbolizes the electron as an arrow and the orbital as a box.
Orbital Diagrams
Spinning charged particles generates a what?
magnetic field.
is a fundamental property of all electrons.
Spin
The electron’s spin adds a fourth quantum
number to the description of electrons in an atom, called the
spin quantum number, m(s)
what values does m(s)
can have values of +½ or −½.
what is pauli exclusion principle
*No two electrons in an atom may have the same set of
four quantum numbers.
*Therefore, no orbital may have more than two electrons,
and they must have opposite spins.
how many electrons are in an orbital
2
how may electrons can s sublevel have?
2
how may electrons can p sublevel have?
6
how may electrons can d sublevel have?
10
how may electrons can f sublevel have?
14
Electron-Electron interactions lead to:
–Shielding
–Penetration
describes the attractions
and repulsions between charged particles.
Coulomb’s law
what is important about Coulomb’s law
on notes
These repulsions cause the electron to have
a net reduced attraction to the nucleus;
shielding
The total amount of attraction that an
electron feels for the nucleus is called the
effective nuclear charge
The what an electron is to the nucleus,
the more attraction it experiences.
closer
The better an outer electron is at what
through the electron cloud of
inner electrons, the more attraction it will
have for the nucleus.
penetrating
related to the orbital’s radial distribution
function.
degree of penetration
Penetration and shielding cause the energies of sublevels in the same principal level to what?
not be degenerate
where are the effects of penatration important
in the forth and fifth prinicple levels
The energy separations between one set of orbitals
and the next become smaller beyond the
4s
For multi-electron atoms, the energies of the
sublevels are
split not degenerate
why are multi-electron atoms, the energies of the
sublevels split?
shielding and penetration
what do orbitals in sublevels do?
degenerate
energy levels and sublevels fill from what to what
low to high
energy levels and sublevels fill from lowest energy to
high:
energy levels and sublevels fill from lowest energy to
high:
no more than two electrons per orbital.
Pauli exclusion principle
When filling degenerate orbitals, place one electron in
each orbital before completing electron pairs.
Hund’s Rule
listing of the
sublevels in order of filling with the number of
electrons in that sublevel written as a
superscript.
The electron configuration
Electrons in all the sublevels with the
highest principal energy shell are called the
valence electrons