Preparation:
1. Vocabulary - describe in your own words. Some Examples: atom, molecule, compound, alloy, mixture, organic molecule, isotope, vapor, metal, gas, fume, smoke, liquid, fluid, organic molecule, halogens, rare earth metals, electron shell vs. electron cloud, atomic number, atomic weight, element
2. Bohr models - I'll give you an element, you draw the neutral atom. Or the reverse, I give you the Bohr model, you tell me what it is.
2b. Parts of an atom
3. Atomic numbers - Example: what is the atomic number for boron? What is the atomic weight of chlorine?
4. Chemical (element) symbols and the names of the elements. Example: Name these elements: S, N, He, Hg, Pt, U, B, Be, Cd, Pb.
5. Write symbols if I give you the name: silicon, bromine, aluminum, etc.
6. Chemical trivia: Example - what elements are found in table salt, seashells, graphite, charcoal, tin foil (trick question).
7. Definition of density. I might give you a simple math problem like what is the density of a chunk of coal if it weighs nine pounds and has a volume of 0.25 cubic feet? What is the density if the coal is not coal but aluminium instead?
8. If I provide the chemical structure for a substance, can you determine the molecular weight?
That should do it! Good luck my friend.
October 15, 2009
September 28, 2009
Carbon 14
You asked for an easy explanation
The original question asked for an easy way to explain it, so I'm going to try. Here goes . . . .
All organic matter contains carbon, which is an element. But there are different types of carbon, called isotopes.
The most common isotope is carbon-12 (or 12C), which (according the article) makes up 98.89 percent of the naturally occurring carbon. There's carbon-13, or 13C, which is much rarer, accounting for only 1.11 percent, and then there's carbon-14, or 14C, which makes up a ridiculously tiny fraction of existing carbon. (The periodic table of the elements also reflects the existence of isotopes by showing a weighted average for the atomic weight of each element, but I digress.)
The first two isotopes, 12C and 13C, are stable, but 14C is unstable; that is, it's radioactive!
So far, so good. Nothing hard to get your brain around.
Living organic matter will have steady and predictable concentrations of each isotope of carbon, pretty much the percentages mentioned above. But dead stuff won't. After something dies, the 14C decays over time (because it is radioactive) and doesn't replenish as it would in a live specimen because the dead thing isn't eating and breathing or otherwise exchanging molecules with the outside world anymore). In other words, the amount of 14C in dead organic matter will grow smaller. And since scientists know exactly how long an amount of 14C takes to decay, they can compare the amount of 14C in a specimen to the amount of 14C a modern piece of organic matter and calculate the age of the specimen. Since it takes 5,568 years for an amount of 14C to decay by 50 percent (half), if a specimen has one half the amount of 14C as a modern piece of organic matter might have, we conclude it is about 5,568 years old.
Here's an analogy:
Imagine you have a gallon of water to which you add one ounce of blue dye. And say that every 5,568 years you add another gallon of water to the mixture. Doing that basically cuts the concentration of blue dye in half. You then take a gallon of that diluted mixture and add another gallon of pure water to it 5,568 years later. The concentration of blue dye is cut in half again. Now imagine repeating this process for quite some time. If you take a sample of the diluted water and measure the concentration of blue dye, you will be able to determine how many dilutions took place, and since you know the dilutions happen every 5,568 years, you can estimate how old the sample is.
See link below for more information.
Answer
Carbon-14 builds up in living tissue at a constant rate and starts to break down when the tissue dies. Scientists can measure the amount of carbon-14 in a piece of old wood for instance, and say that because there is only a certain amount left, the tree died 1000 years ago.
The original question asked for an easy way to explain it, so I'm going to try. Here goes . . . .
All organic matter contains carbon, which is an element. But there are different types of carbon, called isotopes.
The most common isotope is carbon-12 (or 12C), which (according the article) makes up 98.89 percent of the naturally occurring carbon. There's carbon-13, or 13C, which is much rarer, accounting for only 1.11 percent, and then there's carbon-14, or 14C, which makes up a ridiculously tiny fraction of existing carbon. (The periodic table of the elements also reflects the existence of isotopes by showing a weighted average for the atomic weight of each element, but I digress.)
The first two isotopes, 12C and 13C, are stable, but 14C is unstable; that is, it's radioactive!
So far, so good. Nothing hard to get your brain around.
Living organic matter will have steady and predictable concentrations of each isotope of carbon, pretty much the percentages mentioned above. But dead stuff won't. After something dies, the 14C decays over time (because it is radioactive) and doesn't replenish as it would in a live specimen because the dead thing isn't eating and breathing or otherwise exchanging molecules with the outside world anymore). In other words, the amount of 14C in dead organic matter will grow smaller. And since scientists know exactly how long an amount of 14C takes to decay, they can compare the amount of 14C in a specimen to the amount of 14C a modern piece of organic matter and calculate the age of the specimen. Since it takes 5,568 years for an amount of 14C to decay by 50 percent (half), if a specimen has one half the amount of 14C as a modern piece of organic matter might have, we conclude it is about 5,568 years old.
Here's an analogy:
Imagine you have a gallon of water to which you add one ounce of blue dye. And say that every 5,568 years you add another gallon of water to the mixture. Doing that basically cuts the concentration of blue dye in half. You then take a gallon of that diluted mixture and add another gallon of pure water to it 5,568 years later. The concentration of blue dye is cut in half again. Now imagine repeating this process for quite some time. If you take a sample of the diluted water and measure the concentration of blue dye, you will be able to determine how many dilutions took place, and since you know the dilutions happen every 5,568 years, you can estimate how old the sample is.
See link below for more information.
Answer
Carbon-14 builds up in living tissue at a constant rate and starts to break down when the tissue dies. Scientists can measure the amount of carbon-14 in a piece of old wood for instance, and say that because there is only a certain amount left, the tree died 1000 years ago.
1.5 - Isotope and Carbon Dating
Lesson Components
1. Check out Acahualinca, Kennewick Man, and Roopkund. Make notes in your comp book. How was C-dating used?
2. Determine C14/C12 ratio in our sample of frozen mammouth. I'm going to remove jellybeans when you're not looking and replace them with seeds. Each day represents 125 years of passing time. What is the half-life of the C14 jellybean? Make a plot of (C12/C14) vs. time. We'll discuss.
3. Watch: http://www.youtube.com/watch?v=31-P9pcPStg
4. Read How Carbon-14 Dating Works at HowStuffWorks (see handout).
We'll also talk about the Carbon-14 Debunkers/Creationists, politics of science (briefly!), and the Earth really is older than 5,000 years.
What are some of the challenges of carbon dating?
Draw solar system diagrams for C14 and C12. How do they vary?
Know these definitions and write them in your comp book:
isotope
radiometric dating
radioactive decay
carbon exchange reservoir
half-life
1. Check out Acahualinca, Kennewick Man, and Roopkund. Make notes in your comp book. How was C-dating used?
2. Determine C14/C12 ratio in our sample of frozen mammouth. I'm going to remove jellybeans when you're not looking and replace them with seeds. Each day represents 125 years of passing time. What is the half-life of the C14 jellybean? Make a plot of (C12/C14) vs. time. We'll discuss.
3. Watch: http://www.youtube.com/watch?v=31-P9pcPStg
4. Read How Carbon-14 Dating Works at HowStuffWorks (see handout).
We'll also talk about the Carbon-14 Debunkers/Creationists, politics of science (briefly!), and the Earth really is older than 5,000 years.
What are some of the challenges of carbon dating?
Draw solar system diagrams for C14 and C12. How do they vary?
Know these definitions and write them in your comp book:
isotope
radiometric dating
radioactive decay
carbon exchange reservoir
half-life
September 15, 2009
September 11, 2009
1.1 - Periodic Table of the Elements
As of July 2009, approximately how many elements are there?
How many occur naturally (not synthesized by human monkeys)?
Identify a Group 8B element:
Identify a Period 5 Noble Gas:
Sodium, Lithium and Potassium are in what family?
Bromine and Iodine are in what family?
What is the symbol for uranium?
What are the symbols for gold and silver?
What are the symbols for nitrogen, carbon and oxygen?
Which is heavier, Gallium or Tin?
What is the atomic mass of selenium?
What is the Latin name for tin?
What is the symbol for tin?
What is heavier, a molecule consisting of four hydrogen atoms and one carbon atom, or a molecule of water?
List the symbols for ten metals:
List two metals that are magnetic:
Listen to Tom Lehrer’s Song, the Elements on YouTube
How many protons does an atom of carbon have?
How many neutrons are in Carbon-12? vs Carbon-14?
How many occur naturally (not synthesized by human monkeys)?
Identify a Group 8B element:
Identify a Period 5 Noble Gas:
Sodium, Lithium and Potassium are in what family?
Bromine and Iodine are in what family?
What is the symbol for uranium?
What are the symbols for gold and silver?
What are the symbols for nitrogen, carbon and oxygen?
Which is heavier, Gallium or Tin?
What is the atomic mass of selenium?
What is the Latin name for tin?
What is the symbol for tin?
What is heavier, a molecule consisting of four hydrogen atoms and one carbon atom, or a molecule of water?
List the symbols for ten metals:
List two metals that are magnetic:
Listen to Tom Lehrer’s Song, the Elements on YouTube
How many protons does an atom of carbon have?
How many neutrons are in Carbon-12? vs Carbon-14?
September 09, 2009
1.0 Periodic Table of Elements
Attend lecture and discussion with Master Kusa.
Keep notes and questions in your science comp book.
Read Wiki's "periodic table"
Try
http://www.americanelements.com/
and
http://mistupid.com/chemistry/periodictable.htm
Listen to Tom Lehrer's Song, The Elements
Slide show at:
States of Matter #8 (ten slides)
http://science-class.net/PowerPoints/statesofmatter.ppt
Element or Compound (let's do this together)
http://tre.ngfl.gov.uk/uploads/materials/16659/8E%20lesson%204%205.ppt
Hands-on with Master Kusa
Fun Practice Quiz
http://www.docbrown.info/page03/3_34ptable/ptableQmc.htm
Keep notes and questions in your science comp book.
Read Wiki's "periodic table"
Try
http://www.americanelements.com/
and
http://mistupid.com/chemistry/periodictable.htm
Listen to Tom Lehrer's Song, The Elements
Slide show at:
States of Matter #8 (ten slides)
http://science-class.net/PowerPoints/statesofmatter.ppt
Element or Compound (let's do this together)
http://tre.ngfl.gov.uk/uploads/materials/16659/8E%20lesson%204%205.ppt
Hands-on with Master Kusa
Fun Practice Quiz
http://www.docbrown.info/page03/3_34ptable/ptableQmc.htm
June 24, 2009
DRAFT Proposed Yearly Curriculum
1: The student knows and applies scientific concepts and principles to understand the properties, structures, and changes in physical, earth/space, and living systems.
1.1: Understand how properties are used to identify, describe, and categorize substances, materials, and objects and how characteristics are used to categorize living things.
1.1.2: Understand the positions, relative speeds, and changes in speed of objects.
1.1.2.b: Describe an object’s motion as speeding up, slowing down, or moving with constant speed using models, numbers, words, diagrams, and graphs.
Distance-Time GraphsDistance-Time and Velocity-Time Graphs
1.1.2.c: Measure and describe the speed of an object relative to the speed of another object.
Distance-Time GraphsDistance-Time and Velocity-Time Graphs
1.1.5: Understand how to classify rocks, soils, air, and water into groups based on their chemical and physical properties.
1.1.5.a: Describe properties of minerals and rocks that give evidence of how they were formed (e.g., crystal size and arrangement, texture, luster, cleavage, hardness, layering, reaction to acid).
Rock Classification
1.1.5.c: Describe how Earth’s water (i.e., oceans, fresh waters, glaciers, ground water) can have different properties (e.g., salinity, density).
Water Cycle
1.2: Understand how components, structures, organizations, and interconnections describe systems.
1.2.1: Analyze how the parts of a system interconnect and influence each other.
1.2.1.a: Describe the flow of matter and energy through a system (i.e., energy and matter inputs, outputs, transfers, transformations).
Energy Conversion in a System
1.2.4: Understand the components and interconnections of Earth's systems.
1.2.4.a: Describe the components of the Earth’s systems (i.e., the core, the mantle, oceanic and crustal plates, landforms, the hydrosphere and atmosphere).
Plate Tectonics
1.2.4.b: Describe the interactions among the components of Earth’s systems (i.e., the core, the mantle, oceanic and crustal plates, landforms, the hydrosphere and atmosphere).
Plate Tectonics
1.3: Understand how interactions within and among systems cause changes in matter and energy.
1.3.1: Understand factors that affect the strength and direction of forces.
1.3.1.b: Describe how forces acting on an object may balance each other (e.g., the downward force of gravity on an object sitting on a table is balanced by an upward force from the table).
Atwood Machine
Fan Cart Physics
Pith Ball Lab
Uniform Circular Motion
1.3.1.c: Measure and describe how a simple machine can change the strength and/or direction of a force (i.e., levers and pulleys).
Pulley LabTorque and Moment of Inertia
1.3.2: Understand how balanced and unbalanced forces can change the motion of objects.
1.3.2.a: Describe how an unbalanced force changes the speed and/or direction of motion of different objects moving along a straight line, 2nd Law of Motion (e.g., a larger unbalanced force is needed to equally change the motion of more massive objects).
Atwood MachineFan Cart PhysicsInclined Plane - Sliding ObjectsRoller Coaster Physics
1.3.2.b: Describe how frictional forces act to stop the motion of objects.
Roller Coaster Physics
1.3.2.c: Investigate and describe the balanced and unbalanced forces acting on an object (e.g., a model car speeding up on a table has both an unbalanced force pulling it forward and a gravitational force pulling it down balanced by the table pushing upward).
Atwood Machine
Fan Cart Physics
Pith Ball Lab
Roller Coaster Physics
Uniform Circular Motion
1.3.2.d: Investigate and describe pressure differences that result in unbalanced forces moving objects (e.g., pressure differences cause forces that move air masses, move blood through the heart, cause volcanic eruptions).
Atwood Machine
Fan Cart Physics
Roller Coaster Physics
Uniform Circular Motion
1.3.3: Understand that matter is conserved during physical and chemical changes.
1.3.3.a: Observe and describe evidence of physical and chemical changes of matter (e.g., change of state, size, shape, temperature, color, gas production, solid formation, light).
Density Experiment: Slice and DiceFreezing Point of Salt Water
1.3.3.b: Observe and describe that substances undergoing physical changes produce matter with the same chemical properties as the original substance and the same total mass (e.g., tearing paper, freezing water, breaking wood, sugar dissolving in water).
Freezing Point of Salt Water
1.3.3.c: Observe and describe that substances may react chemically to form new substances with different chemical properties and the same total mass (e.g., baking soda and vinegar; light stick mass before, during, and after reaction).
Balancing Chemical EquationsChemical Equation BalancingLimiting Reactants
1.3.4: Understand the processes that continually change the surface of the Earth.
1.3.4.b: Describe how heat (thermal) energy flow and movement (convection currents) beneath Earth’s crust cause earthquakes and volcanoes.
Plate Tectonics
1.3.4.c: Describe how constructive processes change landforms (e.g., crustal deformation, volcanic eruption, deposition of sediment).
Rock Cycle
1.3.4.e: Describe the processes involved in the rock cycle (e.g., magma cools into igneous rocks; rocks are eroded and deposited as sediments; sediments solidify into sedimentary rocks; rocks can be changed by heat and pressure to form metamorphic rocks).
Rock Cycle
1.3.5: Understand how fossils and other evidence are used to document life and environmental changes over time.
1.3.5.c: Describe how fossils and other artifacts provide evidence of how life has changed over time (e.g., extinction of species).
Human Evolution - Skull Analysis
1.3.6: Analyze the relationship between weather and climate and how ocean currents and global atmospheric circulation affect weather and climate.
1.3.6.a: Compare weather and climate.
Coastal Winds and Clouds
Seasons Around the World
Seasons in 3DSeasons: Earth, Moon, and Sun
Seasons: Why do we have them?
1.3.6.b: Explain the effect of the water cycle on weather (e.g., cloud formation, storms).
Water Cycle
1.3.6.c: Explain how ocean currents influence the atmosphere in terms of weather and climate.
Coastal Winds and Clouds
1.3.8: Understand how individual organisms, including cells, obtain matter and energy for life processes.
1.3.8.d: Describe that both plants and animals extract energy from food, but plants produce their own food from light, air, water, and mineral nutrients, while animals consume energy-rich foods.
Cell Energy CycleFood ChainPhotosynthesis Lab
1.3.9: Understand how the theory of biological evolution accounts for species diversity, adaptation, natural selection, extinction, and change in species over time.
1.3.9.a: Describe how fossils show that extinction is common and that most organisms that lived long ago have become extinct.
Natural Selection
1.3.9.b: Describe how individual organisms with certain traits are more likely than others to survive and have offspring (i.e., natural selection, adaptation).
Evolution: Mutation and SelectionNatural Selection
1.3.9.c: Describe how biological evolution accounts for the diversity of species developed through gradual processes over many generations.
Human Evolution - Skull Analysis
1.3.10: Understand how organisms in ecosystems interact with and respond to their environment and other organisms.
1.3.10.a: Describe how energy flows through a food chain or web.
Food Chain
1.3.10.b: Describe how substances such as air, water, and mineral nutrients are continually cycled in ecosystems.
Water Cycle
1.3.10.c: Explain the role of an organism in an ecosystem (e.g., predator, prey, consumer, producer, decomposer, scavenger, carnivore, herbivore, omnivore).
Food Chain
1.1: Understand how properties are used to identify, describe, and categorize substances, materials, and objects and how characteristics are used to categorize living things.
1.1.2: Understand the positions, relative speeds, and changes in speed of objects.
1.1.2.b: Describe an object’s motion as speeding up, slowing down, or moving with constant speed using models, numbers, words, diagrams, and graphs.
Distance-Time GraphsDistance-Time and Velocity-Time Graphs
1.1.2.c: Measure and describe the speed of an object relative to the speed of another object.
Distance-Time GraphsDistance-Time and Velocity-Time Graphs
1.1.5: Understand how to classify rocks, soils, air, and water into groups based on their chemical and physical properties.
1.1.5.a: Describe properties of minerals and rocks that give evidence of how they were formed (e.g., crystal size and arrangement, texture, luster, cleavage, hardness, layering, reaction to acid).
Rock Classification
1.1.5.c: Describe how Earth’s water (i.e., oceans, fresh waters, glaciers, ground water) can have different properties (e.g., salinity, density).
Water Cycle
1.2: Understand how components, structures, organizations, and interconnections describe systems.
1.2.1: Analyze how the parts of a system interconnect and influence each other.
1.2.1.a: Describe the flow of matter and energy through a system (i.e., energy and matter inputs, outputs, transfers, transformations).
Energy Conversion in a System
1.2.4: Understand the components and interconnections of Earth's systems.
1.2.4.a: Describe the components of the Earth’s systems (i.e., the core, the mantle, oceanic and crustal plates, landforms, the hydrosphere and atmosphere).
Plate Tectonics
1.2.4.b: Describe the interactions among the components of Earth’s systems (i.e., the core, the mantle, oceanic and crustal plates, landforms, the hydrosphere and atmosphere).
Plate Tectonics
1.3: Understand how interactions within and among systems cause changes in matter and energy.
1.3.1: Understand factors that affect the strength and direction of forces.
1.3.1.b: Describe how forces acting on an object may balance each other (e.g., the downward force of gravity on an object sitting on a table is balanced by an upward force from the table).
Atwood Machine
Fan Cart Physics
Pith Ball Lab
Uniform Circular Motion
1.3.1.c: Measure and describe how a simple machine can change the strength and/or direction of a force (i.e., levers and pulleys).
Pulley LabTorque and Moment of Inertia
1.3.2: Understand how balanced and unbalanced forces can change the motion of objects.
1.3.2.a: Describe how an unbalanced force changes the speed and/or direction of motion of different objects moving along a straight line, 2nd Law of Motion (e.g., a larger unbalanced force is needed to equally change the motion of more massive objects).
Atwood MachineFan Cart PhysicsInclined Plane - Sliding ObjectsRoller Coaster Physics
1.3.2.b: Describe how frictional forces act to stop the motion of objects.
Roller Coaster Physics
1.3.2.c: Investigate and describe the balanced and unbalanced forces acting on an object (e.g., a model car speeding up on a table has both an unbalanced force pulling it forward and a gravitational force pulling it down balanced by the table pushing upward).
Atwood Machine
Fan Cart Physics
Pith Ball Lab
Roller Coaster Physics
Uniform Circular Motion
1.3.2.d: Investigate and describe pressure differences that result in unbalanced forces moving objects (e.g., pressure differences cause forces that move air masses, move blood through the heart, cause volcanic eruptions).
Atwood Machine
Fan Cart Physics
Roller Coaster Physics
Uniform Circular Motion
1.3.3: Understand that matter is conserved during physical and chemical changes.
1.3.3.a: Observe and describe evidence of physical and chemical changes of matter (e.g., change of state, size, shape, temperature, color, gas production, solid formation, light).
Density Experiment: Slice and DiceFreezing Point of Salt Water
1.3.3.b: Observe and describe that substances undergoing physical changes produce matter with the same chemical properties as the original substance and the same total mass (e.g., tearing paper, freezing water, breaking wood, sugar dissolving in water).
Freezing Point of Salt Water
1.3.3.c: Observe and describe that substances may react chemically to form new substances with different chemical properties and the same total mass (e.g., baking soda and vinegar; light stick mass before, during, and after reaction).
Balancing Chemical EquationsChemical Equation BalancingLimiting Reactants
1.3.4: Understand the processes that continually change the surface of the Earth.
1.3.4.b: Describe how heat (thermal) energy flow and movement (convection currents) beneath Earth’s crust cause earthquakes and volcanoes.
Plate Tectonics
1.3.4.c: Describe how constructive processes change landforms (e.g., crustal deformation, volcanic eruption, deposition of sediment).
Rock Cycle
1.3.4.e: Describe the processes involved in the rock cycle (e.g., magma cools into igneous rocks; rocks are eroded and deposited as sediments; sediments solidify into sedimentary rocks; rocks can be changed by heat and pressure to form metamorphic rocks).
Rock Cycle
1.3.5: Understand how fossils and other evidence are used to document life and environmental changes over time.
1.3.5.c: Describe how fossils and other artifacts provide evidence of how life has changed over time (e.g., extinction of species).
Human Evolution - Skull Analysis
1.3.6: Analyze the relationship between weather and climate and how ocean currents and global atmospheric circulation affect weather and climate.
1.3.6.a: Compare weather and climate.
Coastal Winds and Clouds
Seasons Around the World
Seasons in 3DSeasons: Earth, Moon, and Sun
Seasons: Why do we have them?
1.3.6.b: Explain the effect of the water cycle on weather (e.g., cloud formation, storms).
Water Cycle
1.3.6.c: Explain how ocean currents influence the atmosphere in terms of weather and climate.
Coastal Winds and Clouds
1.3.8: Understand how individual organisms, including cells, obtain matter and energy for life processes.
1.3.8.d: Describe that both plants and animals extract energy from food, but plants produce their own food from light, air, water, and mineral nutrients, while animals consume energy-rich foods.
Cell Energy CycleFood ChainPhotosynthesis Lab
1.3.9: Understand how the theory of biological evolution accounts for species diversity, adaptation, natural selection, extinction, and change in species over time.
1.3.9.a: Describe how fossils show that extinction is common and that most organisms that lived long ago have become extinct.
Natural Selection
1.3.9.b: Describe how individual organisms with certain traits are more likely than others to survive and have offspring (i.e., natural selection, adaptation).
Evolution: Mutation and SelectionNatural Selection
1.3.9.c: Describe how biological evolution accounts for the diversity of species developed through gradual processes over many generations.
Human Evolution - Skull Analysis
1.3.10: Understand how organisms in ecosystems interact with and respond to their environment and other organisms.
1.3.10.a: Describe how energy flows through a food chain or web.
Food Chain
1.3.10.b: Describe how substances such as air, water, and mineral nutrients are continually cycled in ecosystems.
Water Cycle
1.3.10.c: Explain the role of an organism in an ecosystem (e.g., predator, prey, consumer, producer, decomposer, scavenger, carnivore, herbivore, omnivore).
Food Chain
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