Chem 151 chapter 2

mass

the measure of the quantity of matter in an object (unchanged)

Weight

the measurement of attraction between an object and a gravitational field (changes based on gravitational field)

Accuracy

how close an answer is to an expected or known value

Precision

how close a series of measurements are to one another

atomic number

Number of protons (small number)

mass number

sum of the protons and neutrons (big number)

electrons are...

10,000x smaller than protons and neutrons

Isotopes

same number of protons but different number of neutrons resulting in different mass number

3 hydrogen isotopes

H1 H2 H3

weighted average

the mass reported on periodic table. weighted towards greatest abundance on earth

Family/Group

a vertical column of elements in the periodic table

group 1

alkali earth metals (+1)

group 2

Alkaline Earth Metals (+2)

middle groups

transition (+3, +/-4, -3, -2)

group 7

Halogens -1

group 8

Nobel gases (0)

period

A horizontal row of elements in the periodic table

Law of conservation of mass

Lavoisier; mass is neither created nor destroyed

law of definite proportion/ law of constant composition

proust; a given compound always contains the same proportion of elements

Law of Multiple Proportions

Dalton; compounds can always be reduced to small whole number ratios of elements

daltons atomic theory

1. each element is made up of tiny particles called atoms

2. the atoms of a given elementary identical, but different from the atoms of another element

3. compounds are formed when atoms of different elements combine, and a given compound always has the same relative numbers and types of atoms

4. chemical reactions involve reorganization of atoms (changes in the ways that atoms are bound), but the atoms are not changed in the reaction.

Thomson model of the atom

cathode ray tube experiment

plumb pudding model

still study because: charge-to-mass ratio of an electron

Millikan model of the atom

oil drop experiment

still study because: came up with mass of an electron

Rutherford model

gold foil experiment nuclear model of an atom (still use today)

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

7 diatomic elements

2 nonmetals

-use prefixes to indicate number of atoms

- 2nd element ends in "ide"

-no mono on first element

don't make neutral compounds

Binary salts

-make neutral compound

-2nd element ends in "ide"

-metal listed first

H

hydrogen

C

carbon

Ne

neon

Si

silicon

Ar

argon

Mn

manganese

Cu

copper

Pd

palladium

Ba

barium

Pb

lead

He

helium

N

nitrogen

Na

sodium

P

phosphorus

K

potassium

Fe

iron

Zn

zinc

Ag

silver

Pt

platinum

Li

lithium

O

oxygen

Mg

magnesium

S

sulfur

Ca

calcium

Co

cobalt

Br

bromine

Sn

tin

Au

Gold

U

uranium

B

boron

F

Flourine

Al

aluminium

Cl

chlorine

Cr

chromium

Ni

nickle

Sr

strontium

I

iodine

Hg

Mercury

1

mono

2

di

3

tri

4

tetra

5

penta

6

hexa

7

hepta

8

octa

9

nona

10

deca

NH4 +

ammonium

CN -

cyanide

OH -

hydroxide

MnO4 -

permanganate

C2H3O2 -

Acetate

NO3 -

Nitrate

NO2 -

Nitrite

CO3 2-

Carbonate

SO4 2-

Sulfate

SO3 2-

Sulfite

S2O3 2-

Thiosulfate

PO4 3-

Phosphate

CrO4 2-

Chromate

Cr2O7 2-

Dichromate