Energy & MatterEnergy & Matter2.1, 1.1, 1.2, 1.32.1, 1.1, 1.2, 1.3

1. Energy (2.1)A. Energy: The capacity to do work or produce

heat.1. 7 types of energy:

• mechanical• thermal (heat)• radiant (light)• sound• electrical• chemical• nuclear

2. Kinetic Energy: Energy of motion.

Ex. thermal,

mechanical

3. Potential Energy: stored energy; determined by position.

Ex. Electrical PE, chemical PE

Potential and Kinetic Energy

4. Energy can be transferred from a system to its surroundings.

Ex. Photosynthesis is light → chemical

Energy Transformations:

5. Energy absorbing changes are called endothermic. If energy is released the change is called exothermic.

B. Measuring Energy:B. Measuring Energy:

1. Common Unit: 1. Common Unit: caloriecalorie The amount of The amount of heatheat needed to raise needed to raise 11 g of water g of water 11 ooC. (One C. (One calorie = 1g°C)calorie = 1g°C)

2. SI Unit for energy: 2. SI Unit for energy: JouleJoule (J) (J)

C. Law of Conservation of Energy:C. Law of Conservation of Energy: Energy is neither Energy is neither ccreatedreated nor nor destroyeddestroyed, it just , it just

changes changes formform. .

Temperature (2.1):Temperature (2.1):

1. Energy can be transferred in the form of 1. Energy can be transferred in the form of

heatheat. .

2. Temperature is a measurement of heat or 2. Temperature is a measurement of heat or

kinetic energykinetic energy. (how fast the average . (how fast the average

particle is moving!)particle is moving!)

Heat vs. Temperature AnimationHeat vs. Temperature AnimationKinetic Energy (Temperature) and MeltingKinetic Energy (Temperature) and Melting

3. Common TemperaturesFahrenheit (F) Celsius (°C) Kelvin (K)

Background InformationPopular

(1686-1736)

scientists

(1701-1744)

SI Unit

Absolute scale

(1824-1907)

Boiling Point of Water 212 100 373

Body Temperature 98.6 37 310

Room Temperature 70 20 293

Freezing Point of Water 32 0 273

Absolute Zero -459.67 -273 0

Room Temp 20°C →

Room Temp 70°F →

← Room Temp 293 K

98.6°F

4. Kelvin:4. Kelvin: °C = K°C = K

5. The zero point on the Kelvin scale is called 5. The zero point on the Kelvin scale is called absolute zeroabsolute zero ( (--273°C) 273°C)

6. All motion of particles 6. All motion of particles stopsstops! Therefore the ! Therefore the kinetickinetic energy is energy is zerozero..

K = °C + 273

°C = K - 273

2. 2. MatterMatter is anything that has is anything that has massmass and takes up and takes up spacespace..1.1. Volume Volume: Amount of : Amount of spacespace an object takes up. an object takes up.

2.2. Mass Mass: Quantity of : Quantity of mattermatter in a substance. in a substance. ConstantConstant everywhere. Ex) the moon everywhere. Ex) the moon

3. 3. WeightWeight: Force produced by : Force produced by gravitygravity acting on a acting on a mass. This is mass. This is differentdifferent in different locations. in different locations.

Mass Vs. WeightMass Vs. Weight

Mass does not depend on gravity. The mass of an object remains the same in all locations.

Weight depends on gravity. Weight equals Mass x gravity. The weight of an object changes with location.Weight and Mass Demo

B. Properties of Matter (1.2):

1. Physical: density, color, melting point, viscosity, surface tension, specific heat

2. Chemical: flammability, reactivity with other

chemicals or air (O2)

C. States of Matter (1.1):

State Shape Volume Movement Structure

Solid definite definite vibrational - slow highly organized - crystal

Liquid indefinite definite translational - medium medium - fluid

Gas indefinite indefinite translational - fast low - random

Plasma is the 4th state of matter – “ionized gas” like the sun

D. Kinetic Theory of Matter (2.1)D. Kinetic Theory of Matter (2.1)

1. 1. GasesGases possess the greatest amount of kinetic energy. possess the greatest amount of kinetic energy.

2. Two factors that determine the state of matter of a 2. Two factors that determine the state of matter of a substance: substance: speed of the particlesspeed of the particles and the and the distance distance between thembetween them..

3. These two factors contribute to the 3. These two factors contribute to the attractionattraction between the between the particles.particles.

4. Substances 4. Substances changechange phasephase when they overcome these when they overcome these attractions.attractions.

5. The overall 5. The overall kinetickinetic energyenergy (temperature) will remain (temperature) will remain constant until the entire substance has completely constant until the entire substance has completely changed phase. changed phase.

6. Heating Curve for Water6. Heating Curve for Water

melting

freezing0

(C)

100Vaporization

(boiling/evaporation)

condensation

Solid

Liquid

Vapor (gas)

Cooling Curve

Heating Curve

E. Changes in Matter (2.1): E. Changes in Matter (2.1):

1.1. Physical Changes Physical Changes:: a. Do NOT change the a. Do NOT change the identityidentity of the substance. of the substance. b. Often change what the b. Often change what the substancesubstance looks like. looks like. c. Examples: c. Examples: cutting, dyeing, changes of statecutting, dyeing, changes of state

States of Matter & Phase Changes

melting

freez

ing

condensation

vaporizationevaporation –at the surface

boiling - throughout

depositionsublimation

Solid

Liquid Gas(Vapor)

States of Matter

Comparison of the three states of matter

Density = .92g/mL

Density = 1.00g/mL

22. Chemical Changes. Chemical Changes::a. Alter the a. Alter the identityidentity of the substance. of the substance.b. The new substance has b. The new substance has different propertiesdifferent properties than the original substance.than the original substance.c. Examples of Chemical Changes: c. Examples of Chemical Changes: burning, rustingburning, rustingd. Signs that a chemical change has occurred:d. Signs that a chemical change has occurred:

1. 1. gas released (bubbles/odor/fizz/smoke)gas released (bubbles/odor/fizz/smoke)2. 2. color change (can be physical too)color change (can be physical too)3. 3. formation of a precipitate (insoluble solid that formation of a precipitate (insoluble solid that

falls out of solution.)falls out of solution.)4. 4. temperature change temperature change (can be physical also) (can be physical also)

F.F. Law of Conservation of Matter (2.2): Law of Conservation of Matter (2.2): Matter is neither Matter is neither createdcreated or or destroyeddestroyed it just changes it just changes formform..

G. Classification of Matter (1.3)G. Classification of Matter (1.3)

1. 1. Pure substancesPure substances: Substances that have a : Substances that have a uniqueunique set of set of

physicalphysical and and chemicalchemical properties. properties.

a. a. ElementsElements: The smallest part of an element is : The smallest part of an element is

an an atomatom..

1. Cannot be separated into 1. Cannot be separated into simpler substancessimpler substances..

2. Represented by 2. Represented by symbolssymbols that have that have 11 or or 22 letters. letters.

Ex) K, Na, Au, Ag, Hg, FeEx) K, Na, Au, Ag, Hg, Fe

(three lettered symbols are temporary)(three lettered symbols are temporary)

3. Examples:3. Examples:

1H

Hydrogen

1.008

Atomic Number: # of protons

Element Symbol: 1 or 2 letters (1st is a capital)

Element Name

Atomic Mass: (weighted average of all an elements’s isotopes)

b. b. CompoundsCompounds::1. Made up of 1. Made up of 22 or more kinds of atoms or more kinds of atoms

chemicallychemically combined in a fixed proportion. combined in a fixed proportion.2. Represented by 2. Represented by formulasformulas..

3. Examples: 3. Examples: CO, COCO, CO22, H, H22OO

2. Mixtures:2. Mixtures:a. a. Heterogeneous MixtureHeterogeneous Mixture: Visibly : Visibly differentdifferent

throughout. Will separate upon standing.throughout. Will separate upon standing.

Ex) Ex) salad dressing (salad dressing (emulsionemulsion), ), chocolate chocolate

chip cookies, sand & water (chip cookies, sand & water (suspensionsuspension))

b. b. Homogeneous MixtureHomogeneous Mixture: The : The samesame

throughout. May be clear, will not separate.throughout. May be clear, will not separate.

Ex) Ex) Kool-aid (Kool-aid (solutionsolution))

milk (milk (colloidcolloid))

gold jewelry (gold jewelry (alloyalloy))

Examples of AlloysExamples of Alloys

Brass is an alloy of copper and zinc.

Steel is an alloy of carbon and iron.

Bronze is an alloy of copper and tin.

Gold – Element & Alloys

Microscopic look at mixtures

Suspensions Colloids Solutions Alloys

ex) sand & water ex) milk ex) Kool-Aid ex) gold jewelry

H. Separating Mixtures (1.3)

1. Heterogeneous Mixtures can be separated by:

a. Filtration- Material remaining on the filter paper is called the residue. The filtrate goes through the filter paper. Ex) sand & water

Separation of Homogeneous Mixtures:

a. Distillation- separates liquids (and 1 solid) by differences in boiling point. The remaining material is called the residue. The material that goes through is called the distillate.

Ex) alcohol & H2O

Another Look at Distillation

• Distillation Demo

• A Closer Look at Distillation

Separation of Homogeneous Mixtures

b. Crystallization- Evaporate liquid and the solid will crystallize. Ex) salt and water

c. Chromatography – used to separate pigments and ink by differences in solubility (density) on a strip of paper.Ex) black ink - rainbow

Another look at Paper Chromatography

3. Separating Compounds:

a. Electrolysis – decomposes a compound into its elements. Ex) water into H2 and O2