che131 final

atom

smallest measurable unit that makes matter

scientific law

summarizing past, and predicting future observations

atomic theory

each element is made out of indestructible atoms

matter

anything that occupies space and has mass

pure substance

definite chem composition, can’t be broken down into simpler substances

mixture

combination of 2 or more substances that are not chemically bonded

homogenous mixture

uniform look, composition is the same throughout substance

heterogenous mixture

nonuniform look, composition varies throughout substance

solids

definite shape and volume

liquid

fixed volume, not shape

gas

no fixed volume or shape

kinetic energy

total energy

law of conservation of eneryg

energy is neither created or destroyed

intensive properties

characteristics independent of amount of substance

extensive properties

characteristics that scale depending on amount of substance

scale invariant

ratio of extensive properties that scale together

sublimation

going from solid to gas

critical point

in phase diagram, where liquid and gas blend at high temp/pressure

mass

measure of mass within an object

weight

measure of gravitational pull on an object

accuracy

how close to actual value

precision

how reproducible

brownian motion

movement of atoms in suspended fluid, due to thermal energy

atomic theory

all matter is composed of atoms

law of conservation of mass

matter is neither created nor destroyed

law of definite proportions

all samples of a compound have the same fixed mass of constituent elements

law of multiple proportions

when two elements form different compounds, it can be expressed as a ratio of whole numbers

cathode rays

stream of electrons produced when a high voltage is applied between 2 electrodes

cathode

negative charged electrode

anode

positive charged electrode

electrostatic forces

electro attractive and repulsive forces

electron

neg charged, exist outside nucleus

radioactivity

emission of small energetic particles from the core of unstable atoms

nuclear theory

the atoms mass and positive charge are contained within the nucleus

neutrons

neutral particles that add mass to an atom

charge of an electron/proton

(±)1.60 × 10^-19

isotypes

atoms with same number of protons, but different neutrons (different masses)

ions

charged particles

cations

positively charged atom

anion

negatively charged atom

the periodic law

when elements are arranged in order of increasing mass, certain sets of properties occur periodically

metals

good conductors, malleable, ductile, lose electrons

nonmetals

poor conductors, gain electrons

metalloids/semimetals

only conduct electricity, mixed properties

transition metals

properties are less predictable, form more than one type of cation

noble gasses

tend to be unreactive

alkali metals

highly reactive metals

alkaline earth metals

reactive metals

halogens

extremely reactive non metals

mol/avogadros #

6.022 × 10²3

ionic bonds

transfer of electron, metal + nonmetal

covalent bonds

sharing of electrons, 2 or more nonmetals

empirical formula

shows a ratio of elements in a compound

molecular formula

actual number of atoms in an element

structural formula

use lines to show bonds between elements

space filling model

represent molecules scaled to size (10^8)

atomic elements

tend to exist in nature, elements with a single atom

molecular elements

do not normally exist in nature, more than 1 atom

formula unit

smallest unit of an ionic compound

oxyanions

ionic compound containing oxygen

hydrates

contain certain amount of water

acids

donate hydrogen when dissolved in water, dissolve many metals

binary acids

hydrogen + nonmetal

oxyacid

nonmetal + oxygen

combustion analysis

burning a substance to figure out the molecular formula

interference

interaction between waves

constructive interference

waves are in phase and combine

destructive interference

waves are out of phase and cancel

diffraction

bending and spreading of waves as they hit an object 

photoelectric effect

observation that metals emit electrons when light is shined upon them

n

principle quantum number, determines energy level of electron

indeterminacy

present circumstances do not necessarily determine future events

l

angular momentum quantum number, determines shape of electron

ml

magnetic quantum number, determines orientation of electron

orbitals

probability distribution maps showing where electrons are likely to be found

ms

spin quantum number, determines spin of electron

phase

the sign of a waves amplitude, positive or negative

pauli exclusion principle

no two identical electrons can have the same four quantum numbers, implies there can only be two electrons per orbit

aufbau principle

electrons fill lower energy orbits before moving to higher energy levels

hunds principle

electrons will fill orbits individually before pairing up

madelung principle

explains the order in which atomic orbits are filled

radial distribution plot 

graphical representation of probability of finding electrons 

degenerate orbitals

orbitals with the same energy within the same subshell

ionization energy

energy required to remove an electron in the gaseous state

electron affinities

energy change associated from gaining an electron in the gaseous state

van der waals radius

radius between non bonded atoms

covalent radius 

radius between bonded atoms 

paramagnetic

has unpaired electrons, is attracted to a magnetic field

diamagnetic

does not have unpaired electrons, is slightly repelled by a magnetic field

lattice energy

energy associated with the formation of a crystalline lattice

born-haber cycle

type of energy cycle used to calculate the lattice enthalpy of an ionic compound

hess’s law

∆E = sum of enthalpy changes of the steps

intermolecular forces 

force in between molecules 

intramolecular forces

force within molecules

electronegativity

ability of an atom to attract electrons to itself

dipole moment

vector quantity indicating polarity in a molecule

resonance structures 

2 or more valid lewis structures that together describe the bonding in a molecule 

formal charge

(valence e) - (nonbonding e + ½ bonding e)

free radicals

molecules with an odd number of electrons

coordinate covalent bond

both electrons in the shared pair come from one atom