Chemistry Exam 1

matter

-has mass

-occupies space

leptons

electrons are made of what

three quarks

protons and neutrons are each formed from _____

quarks and leptons

_____are fundamental constituent of matter

substance

a form of matter that has a uniform and definite composition and distinct chemical properties

elements and compounds

2 types of substances

elements

-made of only one type of atoms

-oxygen, gold, carbon

compounds

-made of two or more elements chemically bonded in fixed ratios

-water, carbon dioxide

mixture

-composed of different types of atoms or molecules that are not chemically bonded

-physically combined structures that can be separated into their original components (ex. milk vinegar, gasoline, etc)

molecule

the smallest entity of a compound having the same proportions of the constituent atoms as does the compound as a whole

chemical properties

-the ability or inability to react and form a new substance (ex. undergo a change in composition)

-becomes evident during, or after a chemical reaction

-can be established only by changing a substance’s chemical identity

chemical changes

-reactants undergo chemical change (composition change) to produce products

-examples: reaction of gasoline with oxygen

evolution of gas, color change, formation of precipitates, and change in temperature

chemical reactions can be indicated by:

heterogeneous mixture

-a substance that’s not uniform in composition and can be easily separated into its parts, with each part retaining its original properties

-ex. salad, mixture of sand and salt

homogenous mixture

-mixture of two or more substances that are evenly distributed throughout and have the same composition throughout a sample

-ex. milk, salt water, air, coffee, etc

filtration, distillation, and chromatography

3 types of physical processes to separate mixtures

filtration

separation of solids by differences in solubility

distillation

separation by differences in boiling points

yuh

just be knowing all the types of chromatography

extensive quantities

increase as the size of the system increases such as length, area, volume, weight or mass, etc.

intensive quantities

independent of the system size such as temperature, density, specific heat capacity, etc

Lavoisier 1774

who discovered law of conservation of mass

proust 1799

who discovered law of constant composition

dalton 1803-1888

who created dalton’s atomic theory

law of conservation of mass

in any chemical reaction the total mass of substances present after the reaction is the same as the total mass of substances before the reaction

law of constant composition

all samples of a compound have the same composition—the same proportions by mass of the constituent elements

found that a given compound always contains the same proportions of elements by mass

dalton’s atomic theory

all atoms of an element are alike in properties but the atoms of one element differ from those of all other elements

in each of their compounds, different elements combine in simple numerical ratios (ex. NaOH (1:1:1), H2O (2:1)

law of multiple proportion

if two elements form more than a single compound, the masses of the one element combined with the fixed mass of the second are in the ratio of small whole numbers

cathode ray tube

what instrument was used to discover the electrons

Milikan’s oil drop experiment

how did we discover the exact electric charge of an electron

rutherford

who identified two types of radiation from radioactive materials

alpha and beta particles

the two types of radiation particles

amu

unit of measurement to express the mass of individual atoms and molecules

isotope

different forms of an element having the same number of protons but different numbers of neutrons

average atomic weight (mass)

average mass of an element based on the naturally occurring isotopes and the relative abundance of these isotopes on earth

ion

atom or group of atoms carrying either negative (anion) or positive (cation) net electric charge

groups

columns are called _____

column

elements with similar chemical and physical properties are in the same_____

periods

rows are called ____

pattern

each period shows a _____ of properties repeated in the next period

18

how many groups in periodic table

F block elements

lanthanides and actinides

alkali metals, alkaline earth metals, transition metals, pnictogens, chalcogens, halogens, and noble gases

order from left to right, names of the periodic table groups

nuclide

the general term for referring to an atom with a particular # of protons, neutrons, and electrons is ___

chemistry

study of chemical compounds

chemical compounds

composed of two or more atoms

ex.) CO, CO2, H20, sucrose (sugar), ascorbic acid (vitamin C), acetylsalicylic acid (Tylenol)

chemical bonding

when atoms approach each other they interact (chemical reaction) and form a bond (be held together)

covalent and ionic

2 types of chemical bonds

covalent bonds

electrons are shared equally between atoms

prevalent between non-metallic atoms

ex.) H-H, C-C, C-H

ionic bonds

electrons are transferred from one atom to another atom to form oppositely charged ions attracted to one another

usually between a metal and a nonmetal

molecular compounds

-all bonds are covalent; typically consist of non-metal atoms (ex. ethane)

ionic compounds

at least one ionic bond; made up of positive and negative ions (ex. sodium chloride)

structural formula

graphic representation of the molecular structure

shows the order in which atoms are bonded together in a molecule and what types of bonds are present

molecular formula

reports on how many and which atoms exist in a molecule of the compound (C2H4O2)

condensed structural formula

a molecular formula in which connectivity is preserved

CH3COOH

empirical formula

simplest formula for a compound; atomic subscripts in a formula are reduced to the lowest whole number ratios (CH2O)