Chemistry Fall Final Review

what are three lab safety rules

no food or drink in lab, wear safety gear, no sitting on the tables

what are the rules for zeros related to significant figures

all numbers other than 0 are significant, if zero is the last number after the decimal point it is significant and all 0's between sig figs are significant

when is a zero not significant

when it is a place holder (ex. 400)

metric prefixes largest to smallest

mega, kilo, hecto, deka, standard(m,g,l), deci, centi, milli, micro, nano

define homogeneous

mixtures that are uniform in composition

ex. of homogeneous mixture

water

define heterogeneous

mixtures that are not uniform throughout

ex. of heterogeneous mixture

chunky peanut butter

intensive property

a property where size doesn't matter because whats in a small piece is the same in a big piece

ex. of intensive property

color, density, melting point, conductivity

physical change

the appearance or form of the matter changes but the kind of matter doesn't

examples of physical change

cutting, bending, freezing, dissolving, boiling, melting

chemical change

when one or more substances change into a new substance

ex. of chemical change

iron rusting, wood burning

define extensive property

the size matters, the difference between a big and small piece

example of extensive property

height, weight, length, volume,

what is a mixture

two or more substances that aren't chemically combined

examples of mixtures

koolaid, salt water, air

what is a compound

two or more atoms in a set ratio

examples of a compound

glucose (C6H12O6), peroxide (H2O2), water (H2O)

what law did Lavoisier propose

he proposed the Law of Conservation of Mass

what does the Law of Definite Proportions state

matter combines in set ratios by mass and elements combine in set rations by mass

what does the Law of Multiple Proportions state

elements combine in small whole number ratios

what does the Law of Conservation of Mass state

matter can neither be created nor destroyed

what subatomic particle did JJ Thomson discover

electrons

what did JJ Thomson use to discover electrons

cathode ray tube

what was the gold foil experiment

it measured how an alpha particle beam is scattered when it strikes a thin metal foil

what was learned from the gold foil experiment

atoms are mainly empty space and there must be a tiny center that is heavy (nucleus)

what was learned about the nucleus in the gold foil experiment

it is positively charged

what is an elements atomic number

the number of protons in the element

what is an elements mass number

the number of protons and neutrons

what is an isotope

atoms of the same element with same number of protons but different number of neutrons (causing different masses)

mass of protons and nuetrons

1

mass of electron

0

what does the principle quantum number represent

size of energy level where the electron is located

what is an octet

s^2p^6

what are valence electrons

the electrons in the outermost level/ending of an electron configuration

what is the number of valence electrons most elements want to acquire

8 electrons

what is the importance of s^2p^6

it represents the ending electron configuration that elements need to be the most stable

what is the Pauli Exclusion Principle

no two electrons in the same atom can have the same set of quantum numbers

what is Hund's rule

place one electron in each orbital before paring them up

what happens when electrons become excited

they jump out to the next energy level

what happens when an excited electron is returning to its ground state

it releases the excess energy by emitting light

what does ROYGBIV represent

red, orange, yellow, green, blue, indigo, violet

at what end of ROYGBIV are the wavelengths the longest with the lowest energy

red

at what end of ROYGBIV are the wavelengths the shortest with the highest energy

violet

what is the Aufbau principle

place electrons in the lowest energy level first

what are the three categories that elements are divided into

metals, non-metals and metalloids

most elements on the periodic table are in which category

metals

do metals gain or lose electrons to become more stable

lose electrons

do non-metals gain or lose electrons to become more stable

gain electrons

what is a metalloid

an element who has metal and nonmetal properties

where are metalloids found on the periodic table

the stair steps

what is special about noble gases

they are already stabilized and have an octet

what group is noble gases in

group 18

what is electronegativity

the attraction for an additional electron

what is the most reactive nonmetal

fluorine (F)

what is the least reactive metal

francium (Fr)

what is the periodic trend in atomic radii as you move down a group

the radii increases as you go down

what group is halogens

group 17

what group is alkali metals

group 1

how did Mendeleev arrange his elements in the first periodic table

by their properties

what is the periodic trend for ionization energy

increases going left to right, decreases going top to bottom

what is the periodic trend for atomic radii

decreases going left to right and increases going top to bottom

what is the periodic trend for electronegativity

increases going left to right and decreases going top to bottom

what is the periodic trend for atomic mass

it increases going both top to bottom and left to right

ammonium

NH4

carbonate

CO3

hydroxide

OH

sulfate

SO4

phosphate

PO4

nitrate

NO3

when writing/naming compounds, which ion goes first

positive ion(cation)

when naming a binary compound what three letters will the name end with

ide

mono

1

di

2

tri

3

tetra

4

penta

5

hexa

6

hepta

7

octa

8

nona

9

deca

10

what is the rule when naming compounds with prefixes

only use a prefix on the first element if has more than one atom

what is the criss cross technique for writing formulas

if the charges dont add up to 0 then criss cross them and write them for the subscripts of the opposite element

what is the empirical formula

the simplest whole number ratio of a compound

definition of mole

the amount of a substance that contains as many particles as there are atoms in 12g of Carbon-12

define stoichiometry

the mass relationships between reactants and products in a chemical reaction