Chemistry 101 Exam 2 University of Alabama

Aufbau Rule

-pattern of orbital filling, with electrons occupying the lowest orbitals first

-1s^2 2s^2 2p^6, ect.

Pauli Exclusion Principle

-no two electrons can have the same four quantum numbers

-each orbital can have a maximum of only 2 electrons with opposite spins

Hund's Rule

-fill levels singlularly first with all of the spins parrallel

-when 2 electrons occupy seperate orbitals of equal energy the repuslive interaction between them is lower because the electrons are spread over a larger space

electron configuration

(1s^2) (2s^2) (2p^6) (3s^2) (3p^6) (4s^2) (3d^10) (4p^6) (5s^2) (5p^6) (6s^2)

metals

-good conductors of heat and electricity

-tend to lose electrons to undergo chemical change

Properties of nonmetals

-tend to be poor conductors of heat and electricity

-tend to gain electrons when undergoing chemical change

mettaloids

-mixed properties

-used to manufacture electronic chips and circuits

Effective Nuclear Charge trend

-increases across a period, decreases down a group

Effective Nuclear charge

-attraction between nucleus and electrons

-zeff= atomic number-number of sheilding electrons

-more electrons=more attraction

Atomic Radii trend

-decreases across a period minus noble gases (because you can only measure their van der waals), increases down a group

Atomic Radii

-larger orbital=further the electrons are from the nucleus

-More effective nuclear charge=smaller atomic radii

Ionic radius trends

-increases down a group and increases across a period

Ionic radius

-difficult to measure with a degree of certainty,

ionization energy trend

increases across a period, decreases down a group

ionization energy

increases uniformly, then with the removal of the first core atom increases a lot

mettalic character trends

decreases across a period, increases down a group

multi electron atoms versus single electron atoms

-in a single electron atom, the orbitals in a given principle shell have the same energy

-in a multi electron atom, the orbitals in a given principle shell have different energies

how to break hunds rule

-have non parallel single electrons in a level

-not filling each electron square in a level before doubling up

how to break pauli's principle

-have the doubled up electrons have parallel spins

-have more than 2 electrons in a level

radius changes with ions of the same atom

the largest radius is x^-1, the smallest is x^+1

paramagnetic

-unpaired electrons (odd number)

-attracted to an external magnetic field

diamagnetic

-paired electrons (even number)

-no net magnetic moment

-weakly repelled by an external magnetic field

metal electronegativity value

-lower electronegativity

ionic compound

-lattice bond

-metal cation(+) and non metal anion (-)

-non directional

-held together by an array of ions

-higher melting point (electrostatic interactions are very strong)

-form hard crystalline solids

covalent compound (molecular compound)

-2 or more non metals

-share electrons

-high ionization energy

-directional

-uses prefixes of di, tri, ect. in naming

-can be found in solid, liquid, and gas forms

shielding electrons

electrons in energy levels below the valence electrons

removal or gain of valence electrons

endothermic reaction (+ energy)= lose electron (metals)

exothermic reaction(- energy)= gain electron (non metals)

electron affinity

-change in energy when a neutral atom gains an electron

-aka the neutral atom's likelihood of gaining an electron

-metals have lower EA

-First EA is negative, second EA is positive

electron affinity trends

-increases across a period, decreases down a group

properties of covalent compounds

- more electrons bonded=shorter bonds

-shorter bonds=stronger

-interaction between bonds is strong but interaction between molecules is weaker

properties of ionic compounds

-no free electrons to conduct electricity (only conducts in molten or liquid states)

-high melting points of ionic solids

orbitals n=1 to n=5

n=1=s orbital, l=0

ml

-only possible values are between +l and - l

orbital shapes

s= sphere

p= 2

d= 4

f= 8

probability density

probability/ unit volume

radical distribution functions

-total probability of finding the electrons within a thing spherical shell at a distance "r" from the nucleus

-(probability/unit volume) * volume of shell at "r"

-1s and 2s vary because there are no nodes in 1s, and with nodes there is 0 probability

-decreases with decreasing "r"

energy of the subshells

n+l (row number is equal to n value)

mendelev significant observation

when elements are arranged accroding to inceasing mass number, certain sets of properties reoccur

columns versus number of electrons

number of colomns is equal to the number of electrons that can fill the particular sublevel of the block

order left to right of the elements

alkali metals, alkali earth metal, transistion metals, chalogens, halogens, noble gases

emiprical formula versus molecular formula

empirical gives the relative number of atoms of each element in a compound, molecular gives the actual

structural formula

wavelength formula

h/mv v=speed h=2.65*10^6

most reactive

group 1 and group 7