chem 1211 acs final

bond order

# of bonds / # of connections

# of electrons in an ion

# of protons +/- charge #

Z-effective

- effective nuclear charge - charge of an electron increases from left to right across a given period. ex. 2p orbital of a nitrogen atom experiences a greater z effect than a 2p orbital of a carbon atom - most effective when comparing electrons in the same shell and subshell for 2 different atoms.

Electron affinity

- energy change when an atom gains an electron - measured in kJ - alkaline earth metals and noble gases are happy with their full orbitals, they do not want to lose or gain any electrons - increased negativity to top right

ionization energy

- energy required to remove an atom - measured in kJ - As radius decreases across a period, the electron you are removing is closer to the nucleus and harder to remove. - outer electrons are farther from nucleus and easier to remove - inversely proportional with atomic radius - increases from bottom to top, and left to right - top right corner will have highest IE

valence electron configuration

- exists in S and P orbitals only! - outer shell electrons

electronegativity

- in general metals are e- givers and have low electronegativities. - nonmetals are electron takers and have high electronegativities - tend to increase across a period and decrease down a group

structure of an atom

- nucleus of an atom contains protons and neutrons - electrons of an atom are located outside of the nucleus - the number of protons of an atom defines the identity of an element - the mass of an atom is determined by the number of protons and neutrons it contains

octet rule exception

1) odd # valence electrons 2) reduced octect (H, Be, B) 3) Expanded octect (go beyond 8e-, beyond 3p orbitals)

homogenous

A mixture, solid, liquid, or gas that contains two or more substances blended evenly throughout. Ex. Just the salt water

formal charge

Charge assigned to an atom in a molecule or polyatmic ion, calculated by (# valence electrons) - (# 1/2 bonding electrons) - (# nonbonding electrons). Molecules containing atoms with lower formal charges tend to be more stable than those with higher formal charges.

paired electrons

DIAMAGNETIC two electrons together in an electron shell

groups and bonding

Group 4A= 4 bonds and 0lp Group 5A= 3 bonds and 1lp Group 6A= 2 bonds and 2lp Group 7A= 1bond and 0 lp

bond angles

NO2- < NO2 < NO2+

unpaired electrons

PARAMAGNETIC single valence electrons that are used for sharing with one another atom in a covalent bond. compare to lone pair 2 unpaired electrons = 1 paired electron

visible light

R-O-Y-G-B-I-V Red= 750nm - Violet= 400nm

to memorize order of waves

Rachel's mom is very large under x-rays gosh

sigma and pi bonds

Single bond has one σ bond. Double bond has one σ bond and one π bond. Triple bond has one σ bond and two π bonds. - sigma bonds include ALL bonds - pi bonds only include double and triple bonds, triple bonds make up two pi bonds.

max # of electrons that can occupy any orbital

TWO

covalent bond

a chemical bond that involves sharing a pair of electrons between atoms in a molecule

pure substance

a sample of matter, either a single element or a single compound, that has definite chemical and physical properties Ex. distilled water, Sodium

Resonance structure

a structure that occurs when it is possible to draw two or more valid electron dot structures that have the same number of electron pairs for a molecule or ion

largest emission of energy levels

anything that decreases to n= 1 n=5 - n=1 > n= 4 - n=1 > n=3 - n= 1 > n=2 - n=1

# of neutrons

atomic mass - # of protons

bond angles of water

closest to 105 degrees

Octet rule exceptions

dont need to fill all 8 valence electrons (octect) - Hydrogen = 2 electrons - Beryllium (Be) = 4 electrons - Boron (B) = 6 electrons

non-polar

even distribution of charge, equal pull

atomic structure periodic trend

every time we move up one group farther to the right, we add one more proton to the nucleus. (the actual nuclear charge, Z, increases by one) and we add one more electron to the valence shell.

hybridization

formation of 4 equivalent, single, covalent bonds

Ionic bond

formed between one element with a high electron affinity and another element with low ionization energy

polar

having a pair of equal and opposite charges; being pulled in different directions

Atomic Radius

increases from right to left and top to bottom bottom left will have greatest atomic radius - z-eff increases across a period

a single photon of light has the least amount of energy in the case of

infrared radiation

AB2

linear 0 lp linear molecular sp 180 ex. BeH2

heterogeneous

localized regions with different properties Ex. a combination of sand, salt, and water - sand on beach and bottom of ocean floor; salt mixed in with the water-you can't see if but you can taste it

metals, nonmetals, metalloids

metals= left side of the periodic table nonmetals= top right side of periodic table metalloids= stair step starting at B of group 3A B - si- ge/as -sb/te - At

quantum numbers

n = ___ l = n-1 ml = [-n...0...+n] ms = +/- .5

valence electrons

number corresponding to group number

AB6

octahedral octahedral molecular zero lone pair 90;180

AB5U

octahedral square pyramidal molecular 1 lone pair 90; 180

AB4U2

octahedral two lp square planar molecular 90; 180 sp3d2

Intensive property

properties not related to size or amount ex. Density

precision of a measurement

proximity of a measured number to other measured values not accurate, but consistent

accuracy of a measurement

proximity of a measured number to the TRUE value met goal but not consistent

extensive property

related to size or amount Ex. Mass

isotopic

same element; # of protons different # of neutrons

isoelectronic

same number of electrons

to show that a solid substance may contain an ionic bond

show it conducts electricity in aqueous solution

orbital shapes

spherical= S-block Dumbbell shaped= P-block Toroidal = D-block Flower= F-block

Isomere

strength increases as we get shorter = same formula different structure

AB2U2

tetrahedral bent/angular molecular geo two lone pairs sp3 < 109

AB3U

tetrahedral one lone pair trigonal pyramidal molecular sp3 < 109

AB4

tetrahedral zero lone pair tetrahedral molecular sp3 109.4

Lewis formation

the ion exists only in one form; an average of the principal structure

ion is drawn three different ways...

the ion exists only in one form; an average of the shown structures. an extra set of electrons changes the bond order around. extra bond is drawing o bond closer and stronger. bond order= #bonds/#connections

Ag vs. Ag1+

the ion has a higher effective nuclear charge, Zeff, than the atom

# of electrons

the same as the number of protons IF it is neutral; anions - add that number to the proton # cations - subtract that number from proton #

AB2U3

trigonal bipyramidal linear molecular 3 lone pair 180

AB3U2

trigonal bipyramidal t shaped molecular 2 lp 90; 180

AB5

trigonal bipyramidal trigonal pipyramidal molecular 0 lp 90;120;180

AB2U

trigonal planar one lone pair bent molecular

AB3

trigonal planar zero lone pair trigonal planar molecular sp2 120 ex. BF3

AB4U

triognal bipyramidal molecular see-saw one lp 90;120;180

bond length

triple bonds= shortest double bonds= longest

Waves

wavelength increases to the left energy increases to the right frequency increases to the right radio - microwave - infrared- visible light - UV light - x-rays - gamma rays