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Energy & Matter. 2.1, 1.1, 1.2, 1.3. 1. Energy (2.1). Energy : The capacity to do work or produce heat . 7 types of energy: • mechanical • thermal (heat) • radiant (light) • sound • electrical • chemical • nuclear. 2. Kinetic Energy : Energy of motion.
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Energy & Matter 2.1, 1.1, 1.2, 1.3
1. Energy (2.1) • Energy: The capacity to do work or produce heat. • 7 types of energy: • mechanical • thermal (heat) • radiant (light) • sound • electrical • chemical • nuclear
2. Kinetic Energy: Energy of motion. Ex. thermal, mechanical
4. Energy can be transferred from a system to its surroundings. Ex. Photosynthesis is light → chemical
5. Energy absorbing changes are called endothermic. If energy is released the change is called exothermic.
B. Measuring Energy: 1. Common Unit: calorie The amount of heatneeded to raise 1g of water 1oC. (One calorie = 1g°C) 2. SI Unit for energy: Joule (J) C. Law of Conservation of Energy: Energy is neither created nor destroyed, it just changes form.
Temperature (2.1): 1. Energy can be transferred in the form of heat. 2. Temperature is a measurement of heat or kinetic energy. (how fast the average particle is moving!) Heat vs. Temperature Animation Kinetic Energy (Temperature) and Melting
98.6°F Room Temp 20°C→ Room Temp 70°F→ ← Room Temp 293 K
K = °C + 273 °C = K - 273 4. Kelvin: °C = K 5. The zero point on the Kelvin scale is called absolute zero (-273°C) 6. All motion of particles stops! Therefore the kinetic energy is zero.
2. Matter is anything that has mass and takes up space. 1. Volume: Amount of space an object takes up. 2. Mass: Quantity of matter in a substance. Constant everywhere. Ex) the moon 3. Weight: Force produced by gravity acting on a mass. This is different in different locations.
Mass 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): Plasma is the 4th state of matter “ionized gas” like the sun/fluorscent lights
D. Kinetic Theory of Matter (2.1) 1. Gasespossess the greatest amount of kinetic energy. 2. Two factors that determine the state of matter of a substance: speed of the particlesand the distance between them. 3. These two factors contribute to the attractionbetween the particles. 4. Substances changephasewhen they overcome these attractions. 5. The overallkineticenergy(temperature) will remain constant until the entire substance has completely changed phase.
6. Heating Curve for Water Vapor (gas) condensation Cooling Curve 100 Vaporization (boiling/evaporation) Liquid freezing 0 Heating Curve Solid (◦C) melting
E. Changes in Matter (2.1): 1. Physical Changes: • a. Do NOT change the identityof the substance. • b. Often change what the substancelooks like. • c. Examples:cutting dyeing changes of state
States of Matter & Phase Changes Solid deposition melting sublimation freezing condensation vaporization evaporation –at the surface boiling - throughout Gas (Vapor) Liquid Gases are in the gaseous state at room temp. Vapors are in the solid or liquid state at room temp.
States of Matter Comparison of the three states of matter
Density = 1.00g/mL @ 4◦C Density = .998 g/mL @ 20ºC Ice Density = .92g/mL
2. Chemical Changes: a. Alter the identityof the substance. b. The new substance has different properties than the original substance. c. Examples of Chemical Changes: burning, rusting d. Signs that a chemical change has occurred: 1. gas released (bubbles/odor/fizz/smoke) 2. color change (can be physical too) 3. formation of a precipitate (insoluble solid that falls out of solution.) 4. temperature change (can be physical also)
Law of Conservation of Matter (2.2): Matter is neither created or destroyed it just changes form. G. Classification of Matter (1.3) 1. Pure substances: Substances that have a uniqueset of physical and chemicalproperties. a. Elements: The smallest part of an element is an atom. 1. Cannot be separated into simpler substances. 2. Represented by symbolsthat have 1or2letters. Ex) K, Na, Au, Ag, Hg, Fe (three lettered symbols are temporary)
3. Examples: Element Symbol: 1 or 2 letters (1st is a capital) 1 H Hydrogen 1.008 b. Compounds: 1. Made up of 2or more kinds of atoms chemicallycombined in a fixed proportion. 2. Represented by formulas. 3. Examples: CO, CO2, H2O, NH3 Atomic Number: # of protons Element Name Atomic Mass: (weighted average of all an elements’s isotopes)
2. Mixtures: a. Heterogeneous Mixture: Visibly different throughout. Will separate upon standing. Ex) salad dressing (emulsion), chocolate chip cookies, sand & water (suspension) b. Homogeneous Mixture: The same throughout. May be clear, will not separate. Ex) Kool-aid (solution) milk (colloid) gold jewelry (alloy)
Examples of Alloys Brass is an alloy of copper and zinc. Bronze is an alloy of copper and tin. Steel is an alloy of carbon and iron.
Suspensions Colloids Solutions Alloys ex) gold jewelry ex) Kool-Aid ex) milk ex) sand & water
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 theresidue. The material that goes through is called the distillate. Ex) alcohol & H2O
Another Look at Distillation • 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
3. Separating Compounds: a. Electrolysis – decomposes a compound into its elements. Ex) water into H2 and O2