MATTER AND ENERGY

MATTER  Matter is anything that has mass and volume  Two forms of matter  Pure Substances  Mixtures

PURE SUBSTANCES  Uniform composition  The same throughout the sample  Two Types  Elements  Compounds

ELEMENTS  Simplest form of matter  Cannot breakdown  Smallest part called atom  Represented using a capital letter or capital letter and lower case letter

COMPOUND  Two or more elements chemically joined in a specific ratio  Can be broken down  Decomposed  Properties of the compound are different than the elements that make it up

MIXTURE  Two or more substances physically joined in any ratio  Keep the properties of the components of the mixture  Two types  Heterogeneous  Homogeneous

Heterogeneous Homogeneous  Visible difference between components (parts)  No visible differences between components (parts)  Called a solution  Represented using (aq) aqueous

PROPERTIES OF MATTER  Physical Properties  Properties that can be observed without changing the substance  Chemical Properties  Properties that show how a substance reacts (changes)

ENERGY  Energy is the driving force behind change  Cannot be created or destroyed  Does change its form  Sound  Chemical  Radiant (light)  Electrical  Atomic (nuclear)  Mechanical  Thermal (heat)

Two types of energy  Kinetic  Energy of motion  Potential  Stored energy

Measurements involving energy  Temperature  Average kinetic energy of particles  Measured using a thermometer (unit: degrees)  Fahrenheit  Celsius  Kelvin  To convert  °F to °C -- use °C = 5/9( °F - 32)  °C to ° F -- use °F = 9/5 °C + 32  °C to K -- use K = °C  K to °C – use K = °C + 273

Measurements involving energy  Calorimetry  Measures the actual energy (q) in a system  Related to mass (m), specific heat capacity (C) and temperature change (∆T)  Measured using a calorimeter (unit: joules)  To calculate energy use  q = m C ∆T  q = m H fusion  q = m H vaporization

C water = 4.18J/g °C H fus = 334J/g H vap = 2260J/g  How many joules are required to heat 40g water at 30°C to 70°C? q = m C ∆T q = 40g x 4.18J/g°C x 40°C q = 6688J  5000J were added to 30g water at 25°C. What is the new temperature? q = m C ∆T 5000J = 30g x 4.18J/g°C x ∆T 5000 = x ∆T ∆T = 39.9 ~ 40 T new = T new = 65°C  How many joules are needed to melt 100g ice at 0°C q = m H fus q = 100g x 334J/g q = 33400J

PHASES OF MATTER  Solids  Liquids  Gases

SOLIDS  Matter that has specific shape and specific volume  Atoms closely packed together o Cannot be compressed

LIQUIDS  Matter that has a specific volume but takes the shape of the container  Atoms are close but have some space between them o Cannot be compressed o Can be poured

GASES  Matter that takes the shape and volume of the container  Atoms have free space between them o Compressible o Can be poured

PHASE CHANGES If energy is added…  Melting o Solid to liquid  Boiling o Liquid to gas  Sublimation o Solid to gas

PHASE CHANGES If energy is removed…  Freezing o Liquid to solid  Condensing o Gas to liquid  Deposition o Gas to solid

PHASE DIAGRAM solid liquid gas melting boiling Heating Curve for a Substance

PHASE DIAGRAM kinetic potential Heating Curve for a Substance

condensing freezing