Chemistry Units 1, 2, and 3

matter

has mass, takes up space

states of matter

solid, liquid, gas, plasma

solid

definite shape and volume

liquid

definite volume, no defined shape

gas

has neither shape nor volume

physical properties

directly measured (extensive (amount changes with matter) and intensive (constant amount))

extensive examples

mass, weight

intensive examples

boiling point, temperature

physical change

any change that does not change what the actual substance is

chemical change

any change that produces new substances with their own unique properties

signs of chemical change

color change, temperature change, new phase, new odor

Law of Conservation of Matter

matter is neither created nor destroyed, it just changes form

substance

general term referring to any pure element or compound

element

A substance that cannot be broken down into any other substance, atom

compound

a substance of 2 or more elements chemically combined, molecule and fu

mixture

a substance of 2 or more elements physically combined

Homogenous

same composition throughout

Hoterogenous

composition varies throughout

kilo

1000base= 1kbase

deci

1base = 10dbase

centi

1base= 100cbase

milli

1base= 1000mbase

1L

1000cm^3, 1000mL, 1 dm^3

density equation

density= mass/ unit volume

precision

reproducibility of measurement

accuracy

how close the measurement is to the true value

John Dalton’s Atomic Theory

All matter is composed of invisible indivisible particles called atoms, atoms of an element are identical, atoms combine in small whole number ratios to form compounds, in chemical reactions atoms are joined separated or rearranged

JJ Thomson

Rays deflected from a negatively charged object, change-to-mass ratio identical regardless of the cathode metal; electrons

Plum-pudding model of the atom

if electrons are negatively charged there needs to be something positive to balance out so the atom becomes neutral, positive part must be most of atom

conclusions from gold foil experiment

center of atoms is a nucleus that has positive charge, very small and dense

summary of subatomic particles: proton

charge: +1, size:1, location: nucleus

summary of subatomic particles: neutron

charge: 0, size: 1, location: nucleus

summary of subatomic particles: electron

charge: -1, size: 1/1840, location: outside nucleus

atomic number

number of protons in an atom/ element (number on periodic table)

Mass Number

number of protons + neutrons in an atom (not on periodic table)

element symbol notation

symbol with mass number as superscript and atomic number as subscript

hyphen notation

name of element with a hyphen and mass number

isotopes

atoms of the same element (same atomic #) but different amount of neutrons (different mass #)

(Average) Atomic Mass

the weighted average of the masses of the different isotopes of an element

Avogadro’s Number

6.022 x 10^-23 particles

Molar Mass

(atomic mass) x grams= 1 mass

Radioactive decay

spontaneous disintegration of a nucleus with emission or particles

Nucleons

protons and neutrons

Nuclide

any atom

Alpha radiation

reduces atomic number by 2 and mass number by 4, sum of superscripts and subscripts equal on both sides of arrow. basically decomposition

Beta radiation

emission of electron from the nucleus, increased atomic number by 1

Gamma reaction

No mass or charge, emitted with alpha or beta particles

positron emission

atomic number decreases by 1; mass number unchanged

electron capture

atomic number decreases by 1; mass number unchanged

Photon

“packet” of light energy

Colors on color scale

ROY G BIV

Wavelength

| length from crest to crest in meters

/\

frequency

sassy v; # of waves that pass a point in one second

velocity= c

c= wavelength x frequency

Energy

E= Planck’s constant x frequency

Niels Bohr

Electron is confined to specific energy levels that correspond to fixed distance from the nucleus- energy of electron is quantized

summary of Bohr atom

atoms of single electron (H+), energy of electron is quantized (not continuous)

Louis de Broglie

electron behaves as a standing wave around nucleus

Werner Heisenberg

Uncertainty Principle: impossible to know location and velocity of small particle (electron) at once

s orbital

spherical. set on 1 on origin

p orbital

dumbbell shaped, set of 3

d orbital

Cloverleaf (4) (dumbbell with a donut), set of 5

f orbital

complex shapes, set of 7

electron configurations

Cr, Mo, Cu, Ag, Au

Dmitri Mendeleev

Grouped elements in order of increasing atomic mass

Henry Moseley

Modern Periodic Law; physical and chemical properties of the elements are periodic functions of their atomic numbers

Group of periodic table

column (vertical)

Period of periodic table

row (horizontal)

Metal characteristics

ductile, good conductors, malleable, shiny

Nonmetal characteristics

nonductile, insulators, brittle, dull

Alkali metals

1st column

Alkaline earth metals

2nd column

Halogens

Flourine, Chlorine, Bromine, Iodine

Noble Gases

18th column

Representative elements

1st and 2nd column, 13th - 18th column

Transition metals

column 3 to 12

Inner transition metals

Lanthanides, Actinides

Lanthanides

8th period

Actinides

9th period

Atomic Radius

Top to Bottom: increase

Left to Right: decrease

Ionic radius

Top to Bottom: increases

Left to Right: small, smaller, very large, small

Ionization energy

Top to Bottom: decreases

Left to Right: increase

Electronegativity

Top to Bottom: decrease

Left to Right: increase