matter in our world. matter made up of atoms atoms that are all the same make an element every...
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Matter in Our World
Matter
Made up of atomsAtoms that are all the same make an
element Every element has different types of atoms
ElementsElement Symbol Element Symbol
Hydrogen H Mg
Oxygen O Br
Sodium Na Nitrogen
K Sulfur
Iodine I Ca
C Boron
Chlorine Zn
Iron Si
Ag Neon
Matter
When elements chemically combine they form compounds The same element can combine Different elements can combine
Matter can be physically combined into mixtures Lots of elements in the same place Lots of compounds in the same place Combination of elements and compounds in the
same place
Matter
Elements, compounds, and molecules are all pure substances
Matter also exists as mixtures Homogenous
Mixtures that look the same throughout Substances are miscible
Heterogeneous Mixtures that you can see the different substances in Substances are immiscible
Matter
Chemical formulas are important for telling us what compounds are made of Sugar – C12H22O11
Carbon
12 atoms
Hydrogen Oxygen
11 atoms22 atoms
Common Compounds
Salt = NaCl Ammonia = NH3
Baking Soda = NaHCO3
Water = H2O Hydrogen Peroxide = H2O2
Bleach = NaOCl Glass = SiO2
Vinegar = CH3COOH
Kinetic Theory
Three main points All matter is made of atoms and molecules These atoms and molecules are always in
motion At high temperatures, particles move faster
At the same temperature, larger atoms and molecules move slower than smaller ones
Kinetic Theory
Used to describe the states of matter Solid Liquid Gas
Changing States
Solid
Atoms move very, very slowlySet volumeSet shape
States of Matter
Liquid
Atoms move aroundSet volumeChanging shapeCan look at viscosity
High viscosity = less flowing
States of Matter
Gas
Atoms move very, very fastChanging volumeChanging shapeExerts pressure on objects
High pressure = lots of movement
States of Matter
Changing States of Matter
Energy makes this happen
Red Energy added
Blue Energy taken
away
Changing States of Matter
Total amount of matter never changes Law of conservation of mass
Total amount of energy never changes Law of conservation of energy
Changes in Matter
Chemical change Changes the make-up of matter
Different matter is made
Physical change Does not change the make-up of matter
Same matter exists – just a different form
Clues to Chemical Change
Change in colorProduction of gasProduction of a solidKey words:
Burn, decay, ‘die’, ripen, rot
Clues to Physical Change
Key words Cut, tear, melt, freeze, dissolve, grind
Properties of Matter
Chemical Properties Only seen during chemical changes Describes how a substance reacts
Reactivity • How easily one substance can form another substance
Examples: flammability, reactivity, ability to tarnish, ability to decay
Properties of Matter
Physical Properties Can be seen without changing the object The same no matter how large or small the
object is
Examples: melting point, boiling point, color, density, smoothness
Density
Amount of mass within a certain amount on space
DensityVolumeMass
=
Density
What is the density of a 0.996 g piece of graphite with a volume of 0.44 cm3?
2.26 g/cm3
Density
A copper penny has a mass of 3.1 g and a volume of 0.35 cm3. What is the density of the penny?
8.86 g/cm3
Density
A bar of sliver has a mass of 68.0 g and a volume of 6.48 cm3. What is the density of silver?
10.49 g/cm3
Density
Sugar has a density of 1.59 g/cm3. What mass of sugar fits into a 140 cm3 bowl?
222.6 g
Density
The density of silver is 10.5 g/cm3. A bracelet made of silver has a volume of 1.12 cm3. What is the bracelet’s mass?
11.76 g
Density
Boron has a density of 2.34 g/cm3. What is the volume of 14.8 g of boron?
6.32 cm3
Density
Mercury has a density of 13.5 g/cm3. What is the volume of 4.62 g of mercury?
0.34 cm3
Density
The density of oak is generally 0.7 g/cm3. If a 35 cm3 piece of wood has a mass of 25 g, is the wood likely to be oak?
0.71 g/cm3