UMICH CHEM 130 Exam #1

Addition/Subtraction Propagation of Error

√a²+b²

Multiplication/Division Propagation of Error

2.0*√(a/3.0)²+(b/1.5)²

Kevlin

Celsius + 273.15

F to C

(F-32)/1.8

C to F

(C x 1.8) + 32

diatomic molecule

H2, N2, O2, F2, Cl2, Br2, I2

Law of Multiple Proportions

if two or more different compounds are composed of the same two elements, then the ratio of the masses of the second element combined with a certain mass of the first element is always a ratio of small whole numbers

Dalton's Atomic Theory

1) elements are composed of atoms. 2) atoms of same element are identical, but differ from other elements. 3) elements can mix together, with always same # and types of atoms 4) chemical reaction is a reorganization of atoms

Avagadro's Hypothesis

equal volumes of gases at the same temperature and pressure contain equal numbers of particles

Thomson

cathode ray tube experiment-mass to charge ratio-plum pudding model

Millikan

Oil Drop Experiment, determined mass and magnitude of the electron

Rutherford

Gold foil experiment, discovered nucleus

Isotope

Atoms of the same element that have different numbers of neutrons

atomic number

number of protons

mass number

the sum of the number of neutrons and protons in an atomic nucleus

ion

A charged atom

speed of light =

wavelength x frequency

v

frequency (Hz)

h

Planck's constant

# of electrons emitted increases with

intensity

KE of electrons increases with

frequency regardless of intensity

KE of electron =

hv(incident J) - hv(threshold J)

minimum energy to remove an electron

hv_0

high energy change =

short wavelength

Bohr Model

model of an atom that shows electrons in circular orbits around the nucleus

Heisenberg uncertainty principle

it is impossible to know exactly both the velocity and the position of a particle at the same time

l=0

S

l=1

P

l=2

d orbital

l=3

f orbital

s orbital

spherical, all values of n, 2 electrons

p orbital

3 dumbbell shaped, n >= 2

d orbital

5 clover shaped, n >= 3

f orbital

7 orbitals, n >= 4

penetration effect

effect that causes electron in 2s orbital to be attracted to nucleus more strongly than an electron in 2p orbital because of small amount of time spent very near the nucleus

Aufbau Principle

An electron occupies the lowest-energy orbital that can receive it

valance electrons

the electrons in the outermost principal energy level of an atom

group 1

alkali metals

group 2

alkaline earth metals

group 7

Halogens

group 8

noble gases

effective nuclear charge trend

increases up and to the right

atomic radius

increases down and to the left

ionization energy

The amount of energy required to remove an electron from an atom

ionization energy trend

increases up and to the right

electron affinity

the energy change that occurs when an electron is acquired by a neutral atom

electron affinity trend

increases up and to the right

ionic bond

metal + nonmetal

bond energy

the energy required to break a chemical bond and form neutral isolated atoms

Coulomb's Law

F=K q₁*q₂/r², magnitude of force between two charges

covalent bond

A chemical bond formed when two atoms share electrons

polar covalent bond

A covalent bond in which electrons are not shared equally

Electronegativity

A measure of the ability of an atom in a chemical compound to attract electrons

electronegativity trend

increases up and to the right

Electronegativity=

(I-EA)/2

Electronegativity=0

covalant

Electronegativity=medium

polar covalant

Electronegativity=large

ionic

How are ions formed?

both ions achieve noble gas configurations

ion size

size of parent atom, more e, less p