Get 2 days of unlimited access
Textbook Notes (270,000)
US (100,000)
UMD (1,000)
Chapter 1

CHEM 131 Chapter 1: Atoms


Department
Chemistry and Biochemistry
Course Code
CHEM 131
Professor
Rastogi
Chapter
1

This preview shows pages 1-2. to view the full 6 pages of the document.
Chemistry*131*
Chapter*1*
Atoms&
*
The*properties*of*matter*are*determined*by*the*structure*of*the*atoms*and*
molecules*that*compose*them.*
*
1.1 A&Particulate&View&of&the&World:&Structure&Determines&Properties&
-*Two*Main*Points*of*chemistry*
Matter*is*particulateit*is*composed*of*particles*
The*structure*of*those*particles*determines*properties*of*matter*
-&Matter*is*anything*that*occupies*space*and*has*mass*
-&Atoms*are*the*basic*particles*that*compose*ordinary*matter*
-*When*atoms*bind*together*in*specific*geometrical*arrangements,*they*form*
molecules&
-&Chemistry*is*the*science*that*seeks*to*understand*the*properties*of*matter*by*
studying*the*structure*of*particles*that*compose*it*
*
1.2 Classifying&Matter:&A&Particulate&View&
-*Substance*is*a*specific*instance*of*matter*(air,*water,*sand)*
-*The*state*of*matter*is*the*first*classification*
Depends*on*the*relative+position+of+particles*and*how+strongly+they+interact*
with*one*another*
-*The*composition*of*matter*is*the*second*classification*
Depends*on*the*type*of*particles*
States*of*Matter*
Solid:*particles*are*fixed*in*place*and*can*only*vibrate*
Liquid:&particles*are*closely*packed*but*can*move*past*each*other,*allowing*
liquid*to*flow*and*take*shape*of*container*
Gas:&particles*are*widely*spaced,*making*gas*compressible*as*well*as*fluid*
Compositions*of*Matter*
Pure&Substance:&
-*Made*up*of*one*type*of*particle*(one*component)*
-*Composition*is*invariant*(does*not*vary*
-*Individual*atoms*or*groups*of*atoms*joined*together*
Ex:*helium*(He),*water*(𝐻!𝑂),*sodium*chloride*(NaCl)*
>&Element*a*substance*that*cannot*be*chemically*broken*down*into*simpler*
substances*(Helium,*He)*
>&Compound*a*substance*composed*of*two*or*more*elements*in*fixed,*definite*
proportions*(Water,*𝐻!𝑂)*
Mixture:&
-*Made*up*of*two*or*more*particles*
-*Composition*can*vary*from*one*sample*to*another*
Ex:*sweet*tea*can*have*a*lot*of*sugar*or*a*little*
Most*Common*
Fixed*Volume*
Fixed*Shape*
Fixed*Volume*
No*Fixed*Shape*
No*Fixed*Volume*
No*Fixed*Shape*

Only pages 1-2 are available for preview. Some parts have been intentionally blurred.

>&Heterogeneous*the*composition*varies*from*one*region*of*the*mixture*to*
another*(water*&*sand,*does*not*mix*uniformly)*
>&Homogeneous*the*composition*is*the*same*throughout*the*mixture*(sweet*
tea,*mixes*uniformly)*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
&
1.3 The&Scientific&Approach&to&Knowledge&
-*Based*on*observation*and*experiment+
-*Can*be*qualitative*(noting/describing*how*a*process*happens)*or*quantitative*
(measuring*or*quantifying*something*about*the*process)*
Hypothesis*à*Experiments*à*Scientific*Law*
-&Scientific&Laws*describe*how*nature*behavesgeneralizations*about*what*nature*
does*
-&Scientific&Theory*a*model*for*the*way*nature*is*and*why+
-*Most*scientific*observations*are*quantifiable*and*use*units*
-*A*unit*is*a*standard*quantity*by*which*to*measure*
Metric*system*
English*system*
International*System*of*Units*(SI)*
*
SI*Base*Units*
Quantity*
Unit*
Symbol*
Length*
M*
Mass*
kg*
Time*
s*
Temperature*
K*
Amount*of*Substance*
mol*
Electric*Current*
A*
Luminous*Intensity*
cd*
*
Matter*
Mixture*
Pure*Substance*
Element*
Compound*
Heterogeneous*
Homogeneous*
Helium:*Particles*
are*atoms*
Water:*
Particles*are*
molecules*
Wet*sand:*two*
types*of*particles*
that*can*be*
distinctly*
separated*
Tea*w/sugar:*two*
types*of*particles*
that*mix*
thoroughly*
together*
You're Reading a Preview

Unlock to view full version