Chem 163: Exam 2

What is the maximum number of electrons can each electron shell hold?

2n^2

How do you find energy of a photon when an electron goes from n=3 to n=2?

(n=3's eV) - (n=2 eV) = (photon eV)

What is the electron capacity of subshell s?

2

What is the electron capacity of subshell p?

6

What is the electron capacity of subshell d?

10

What is the electron capacity of subshell f?

14

Rank the subshells from lowest to highest energy:

s-p-d-f

How do you identify valence electrons?

look at last shell (principle quantum number)

Atomic size Trend:

increases going down group

decreases going across period

first ionization energy trend:

decreases going down group

increases going across period

Ionic Compounds:

formed by attraction of ions with opposite charges (metals and non-metals)

Electrostatic Force:

the attraction or repulsion of particles because of charge

What does coulomb's Law tell us?

the smaller the distance between the charges, the stronger the force holding oppositely charged ions together

Lattice Energy:

sum of electrostatic forces between ions in a lattice

Crystalline Lattice:

material with a highly ordered lattice

Amorphous Lattice:

material with no overall order or structure

Covalent Bond:

bonding that occurs between electrons in one atom and the nucleus of another atom (non-metal to non-metal)

electronegativity trend:

decreases going down group

increases going across period

What does it mean if the bond of atoms have a large difference in electronegativity?

it has polarity (greater deltaEN, greater polarity)

How do we name ionic compounds?

Metal is written is as the element name, non-metal has the suffix

-ide to the name (Lithium Chloride)

How do we deal with transition metals in compounds?

use a roman numeral to indicate the charge to match the anion's charge (Colbalt III Chloride)

How do we name covalent compounds?

the less electronegative element is named first, the second element has the suffix -ide, and each element has a prefix to show how many atoms the element has in the formula (Disulfur Decafluoride)

Prefix for 1 atom:

mono-

Prefix for 2 atoms:

di-

Prefix for 3 atoms:

tri-

Prefix for 4 atoms:

tetra-

Prefix for 5 atoms:

penta-

Prefix for 6 atoms:

hexa-

Prefix for 7 atoms:

hepta-

Prefix for 8 atoms:

octa-

Prefix for 9 atoms:

nona-

Prefix for 10 atoms:

deca-

How do we name covalent compounds with two non-metals?

the less electronegative element is treated like a metal and keeps the elemental name, and the other element has the suffix -ide (Hydrogen Chloride)

How do we name polyatomic ions?

the metal is named first using the elemental name, the polyatomic ion is named second

NH4 +

Ammonium

CH3CO2 -

Acetate

CN -

Cyanide

NO2 -

Nitrite

NO3 -

Nitrate

CO3 2-

Carbonate

HCO3 -

Hydrogen Carbonate

SO3 2-

Sulfite

SO4 2-

Sulfate

HSO4 -

Hydrogen Sulfate

MnO4 -

Permanganate

PO4 3-

Phosphate

HPO4 2-

Hydrogen Phosphate

H2PO4 2-

Dihydrogen Phosphate

ClO -

Hypochlorite

ClO2 -

Chlorite

ClO3 -

Chlorate

ClO4 -`Perchlorate

CrO4 2-

Chromate

Cr2O7 2-

Dichromate

O2 2-

Peroxide

Simple Acid:

an acid that does not contain oxygen

Oxyacid:

an acid that contains oxygen

How do we name a simple acid?

use the prefix hydro- and suffix -ic to the anion

How do we name an oxyacid?

we either replace -ite with -ous acid or replace -ate with -ic acid

Steric Number:

the sum of the number of atoms attached to the central atom plus the number of lone pairs on the central atom

Steric Number: 2 (2+0)

Bond Angle: 180

Molecular Shape: Linear

Steric Number: 3 (3+0)

Bond Angle: 120

Molecular Shape: Trigonal Planar

Steric Number:4 (4+0)

Bond Angle: 109.5

Molecular Shape: Tetrahedral

Steric Number: 4 (3+1)

Bond Angle: 107

Electron-Group Shape: Tetrahedral

Molecular Shape: Pyramidal

Steric Number: 4 (2+2)

Bond Angle: 105

Electron-Group Shape: Tetrahedral

Molecular Shape: Bent

Steric Number: 3 (2+1)

Bond Angle: 118

Electron-Group Shape: Trigonal Planar

Molecular Shape: Bent

Intermolecular Forces:

the forces that hold neighboring molecules together and is determined by molecular shape

Intramolecular Forces:

the forces inside the molecules

Dipole Moment:

the amount of change separated x distance over which it is separated

Polar Vectors:

has a vector greater than 0

Non-polar Vector:

has a vector equal to 0