The Periodic Table Flashcards
periodic law
states that the chemical and physical properties of the elements are dependent, in a periodic way, upon their atomic numbers
periods
rows of the periodic table; represent the principal quantum numbers n=1 through n=7 for the s- and p- block elements
groups
columns of the periodic table; contain elements that have the same electronic configuration in their valence shell
A elements (representative elements)
have their valence electrons in the orbitals of either s or p shells; i.e. Group VA has five valence electrons with configuration s2p3
B elements (nonrepresentative elements)
include both the transition elements and lanthanide and actinide series
transition elements
have valence e- in the s and d shells
lanthanide and actinide series
have their valence e- in s and f subshells
metals
found on the left side and in the middle of the periodic table; lustrous (shiny) solids
metal properties
malleable: ability to be hammered into shapes
ductility: ability to be drawn into wires
- low effective nuclear change, low electronegativity, large atomic radius, small ionic radius, low ionization energy, low electron affinity
oxidation states
charges when forming bonds with other atoms; many transition metals have a multiple
conductors
metals are good conductors easily conduct heat and electricity because their valence electrons are only loosely held on
metal valence electrons
active metals: found in s subshell
transition metals: found in s and d subshell
lanthanide and actinide series: s and f subshells
nonmetals
found predominantly in the upper right side of the periodic table
properties of nonmetals
- generally brittle in solid state
- show little to no metallic luster
- high ionization energies, electron affinities, electronegativies as well as small atomic radii and large ionic radii
- poor conductors
- do not easily give up electrons
metalloids (semimetals)
- share some characteristics with metals and nonmetals
- physical properties vary widely
- dependent on the elements with which they are reacting
effective nuclear charge (Zeff)
electrostatic attraction between valence shell electrons and the nucleus; increases as you move from left to right within the same period; more or less constant within a group
principal quantum number
increases by one each time as one moves down the elements of a given group; valence electrons are further away and held less tightly as this increases
octet rule
elements tend to be most stable with eight electrons in their valence shell; many exceptions
atomic radii trends
-decrease the more right and high up you are
ionic radii
- metals lose electrons and become pos, nonmetals gain electrons and become negative
- metalloids can go in either direction but tend to follow the trend depending on what side of the line they fall on
- nonmetals close to metalloids possess a larger ionic radius
- metals close to metalloid line have a smaller ionic radius
Ionization energy (IE)
energy required to remove an electron from a gaseous species; endothermic process
endothermic process
requires input of heat
ionization energy trends
-increases from left to right across a period and from bottom to top in a group
first ionization energy
energy necessary to remove first electron, forming X+
second ionization energy
energy necessary to remove second electron forming X2+
electron affinity
- energy dissipated by a gaseous species when it gains an electron
- the higher the Zeff between a nucleus and its electrons, the greater the energy release when it gains an electron
- electron affinity increases across a period from left to right
- electron affinity decreases from top to bottom in a group
exothermic reaction
expels energy in the form of heat
electronegativity
- measure of the attractive force that an atom will exert on an electron in a chemical shell
- higher electronegativity means more attraction to electrons in a bond
- increases from left to right and decreases from top to bottom
alkali metals (Group 1A)
- have only one loosely bound valence electron
- Zeff values very low, radius very high
- low electronegativities, low IE, low E-
- readily act with nonmetals or form univalent cations
- active metal
alkaline earth metals (Group IIA)
- have only two loosely bound valence electrons
- Zeff values very low, radius very high
- low electronegativities, low IE, low E-
- readily act with nonmetals or form divalent cations
- active metal
chalcogens (Group VIA, Group 16)
- include both nonmetals and metalloids
- not as reactive as halogens, but crucial for normal biological functions
- 6 valence electrons
- small atomic radii, large ionic radii
- in high concentrations, all can be toxic to humans
halogens (Group VIIA, Group 17)
- highly reactive nonmetals
- seven valence electrons
- very high E- and electron affinity
- especially reactive towards alkali and alkaline earth metals
- not naturally found in neutral sate but rather as halides because they are so reactive
noble gases (Group VIIIA, Group 18) aka inert gases
- minimal reactivity due to their filled valence shells
- high ionization energies, little to no tendency to gain or lose electrons and no measurable electronegativities
- low boiling points, exist as gases at RT
transition metals (Groups IB to VIIIB, Groups 3-12)
- considered to be metals, have low electron affinities, low ionization energies and low E-
- high melting and boiling points, very hard, malleable, good conductors
- have different possible oxidation states
- tend to either associate with water molecules or nonmetals
subtraction frequencies
frequencies of colors that are not absorbed; we observe the complementary color of the frequency that was observed
