Chapter 3 Flashcards
A periodic property
one that is generally predictable based on an element’s position within the periodic table.
periodic law
When the elements are arranged in order of increasing mass, certain sets of properties recur periodically.
family or group
elements have similar properties
electron configuration
shows the particular orbitals that electrons occupy for that atom
ground state
lowest energy state
Pauli exclusion principle
No two electrons in an atom can have the same four quantum numbers.
degenerate
describes two or more electron orbitals with the same value of n that have the same energy
shielding
For multi-electron atoms, any single electron experiences both the positive charge of the nucleus (which is attractive) and the negative charges of the other electrons (which are repulsive).
effective nuclear charge
the difference of the protons and core electrons
aufbau principle
The pattern of orbital filling
Hund’s rule
when filling degenerate orbitals, electrons fill them singly first, with parallel spins
valence electrons
For main-group elements, the valence electrons are those in the outermost principal energy level
core electrons
those in complete principal energy levels and those in complete d and f sublevels.
noble gases
generally inert—they are the most unreactive elements in the entire periodic table. In other words, when a quantum level is completely full, the overall potential energy of the electrons that occupy that level is particularly low.
Metals
lie on the lower left side and middle of the periodic table and share some common properties
Nonmetals
lie on the upper right side of the periodic table. The division between metals and nonmetals is the zigzag diagonal line running from boron to astatine.
metalloids
elements that lie along the zigzag diagonal line that divides metals and nonmetals
alkali metals
all have an outer electron configuration of ns^1. Like sodium, a member of this family, the alkali metals have electron configurations that are one electron beyond a noble gas electron configuration
alkaline earth metals
all have an outer electron configuration of ns^2. They have electron configurations that are two electrons beyond a noble gas configuration.
halogens
all have an outer electron configuration of np^5. Like chlorine, a member of this family, their electron configurations are one electron short of a noble gas configuration.
atomic radius
As we move down a column (or family) in the periodic table, the atomic radius increases.
As we move to the right across a period (or row) in the periodic table, the atomic radius decreases
paramagnetic
an atom or ion that contains unpaired electrons is attracted to an external magnetic field
diamagnetic
An atom or ion in which all electrons are paired is not attracted to an external magnetic field—it is instead slightly repelled
Cations and radius
Cations are much smaller than their corresponding neutral atoms
Anions and radius
Anions are much larger than their corresponding neutral atoms.
isoelectronic series
ions with the same number of electrons.
ionization energy
the energy required to remove an electron from the atom or ion in the gaseous state. Ionization energy is always positive because removing an electron always takes energy.
Trends in First Ionization Energy
First ionization energy starts at a minimum with each alkali metal and rises to a peak with each noble gas.
First ionization energy generally decreases as we move down a column (or family) in the periodic table because electrons in the outermost principal level are increasingly farther away from the positively charged nucleus and are therefore held less tightly.
First ionization energy generally increases as we move to the right across a row (or period) in the periodic table because electrons in the outermost principal energy level generally experience a greater effective nuclear charge .
electron affinity (EA)
the energy change associated with the gaining of an electron by the atom in the gaseous state.
Metallic Character
As we move to the right across a row (or period) in the periodic table, metallic character decreases.
As we move down a column (or family) in the periodic table, metallic character increases.
