View
801
Download
1
Category
Preview:
DESCRIPTION
Citation preview
2.1 What is matter?
Pages 38 - 44
Goal 1
Distinguish between elements and compounds
• Matter– Has mass and volume– Made up of atoms– Examples:
• Not Matter– No mass, no volume– Examples: Light, Sound, Electricity
• Atoms– General name for the smallest particle that
still has properties of an element– Composed of
• Protons• Neutrons• Electrons
• Elements– Atom with specific # of protons– Has a Name
• 6 protons Carbon • 8 protons Oxygen
• Each element has its own properties
– Carbon melting point 3550°C
– Oxygen melting point -218°C
– Hydrogen melting point -259°C
• Compounds
– Two or more different elements chemically combined
• Compounds have own unique properties
– Oxygen freezing point -218°C
– Hydrogen freezing point -259°C
– H2O freezing point 0°C
• Molecules – Smallest unit of substance– Still retains properties of substance– Can be an element– Can be a compound
Goal 2
Interpret and writechemical formulas
• Capital letter – Symbol that denotes an element always
capitalized
O H C P F N
Na Cl Mg Be Li Si
NaCl HNO SiO
• Subscript– Number of atoms of the element– Always after the symbol
O2 H2
H2O HNO3 CO2
C6H12O6
• Big number in front– Number of molecules
• Elements• compounds
5 H2O
• How many molecules? ___
• How many H atoms total? ___
• How many O atoms total? ___
5 H2O
• How many molecules? ___
• How many C atoms? ___
• How many H atoms? ___
• How many O atoms? ___
C6H12O6
Goal 3
Categorize materials aspure substances
ormixtures
• Pure substances– Fixed composition– Definite properties– Cannot by separated by physical actions– Elements– Compounds
• Pure substance examples
O H C
H2O HNO3 CO2
C6H12O6
• Mixtures– Blend of 2 or more pure substances– All properties remain in mixture
• Mixture example: Grape juice– Properties: wet, sweet, purple– Can separate by evaporation
• Heterogeneous mixture– Not uniformly mixed– Can separate / settle apart– Example: orange juice with pulp
• Homogeneous mixture– Uniformly mixed– Will not separate out or settle
• Miscible liquids– Mixture of liquids that dissolve into each other– Evenly mixed– Cannot see the separate liquids
• Immiscible liquids– Cannot dissolve into each other– Can distinguish separate liquids– Such as: Water and oil
Recommended