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