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Matter
Anything that takes up space and has mass
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Mass
is a measure of the quantity of matter
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2 classifications of matter
Pure substance
mixtures
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Pure substance
matter that has a constant composition
Rare in this world (aluminum in a soda can)
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2 types of pure substances
1- elements-- cannot be broken down by chemical reaction -only one type of atom (only zinc or only copper) -building blocks of matter
- 2-compounds--made of more than one type of atom
- -can be broken down by chemcial reaction
- -has specific formual (h20)
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Mixtures
two or more pure substances and may vary in composition
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2 types of mixtures
1- Homogeneous mixture--has uniform composition throughtout called solution(often clear..salt water)
- 2-Heterogeneous mixture--not uniform throughtout
- (salt, pepper, and water)
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elements
- -buildingblocks of matter
- -116 known elements, 83 naturally found (H, Mg, Zn)
- -classified in 2 categories:
- Metal & Nonmetal (by is shine & abaility to conduct electricity)
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Periodic tabel
- Columns=groups/families
- rows=periods
- metals:shiny, conduct heat/electricity
- nonmetals:dull, insulators
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Compound
substances composed of 2 or more elements combined in a definite proportion H20, C2H60, Nacl
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atoms
smallest unit of an element
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molecule
- smallest unit of a compound,
- -made up of 2 or more atoms bond together
H20
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three physical states of matter
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Solid
- (S)
- -fixed shape, fixed volume
- -cannot be compressed unless a lot of force applied
- -particles(atoms/molecules) are fixed in shape (very little motion)
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Liquid
- (l)
- -indefinite shape, takes shape of the container
- -fixed volume, cant be compressed
- -particles NOT in fixed position (constinantly moving)
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Gas
- (g)
- -indefinite shape, takes shape of container (balloon)
- -indefinite volume, can be compressed(expand/contract to fill the container)
- -particles are far apart in rapid motion
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Aqueous(aq)
Dissolved in water (sugar water)
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Physical property vs chemical property
density=mass/volume
Physical-property is something we can observe without changing the composition (cutting into smaller pieces) liquid to a gas ex.odor,taste,hardness,mass,volume,density,temp, conductivity
Chemical-one or more substances converted to into one or more new substances (color change of pennies over time)
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quantitative properties
- Tempertature
- mass
- volume
- density
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Significant Figures
Number of MEANINGFUL digits in a measurement
- -If decimal point; #>1, all digits sigs
- 4.23=3 sigs
- 3.400=4 sigs
- 20.000=5 sigs
- -If #<1, signific. digits start w/ first non zero # after decimal point
- 0.004123=4 sigs
- 0.0210=3 sigs
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