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Changes in Earth's Atmosphere Unit Overview

Unit Summary:

 

Weather phenomena capture our attention on a daily basis. This unit focuses on understanding climate,  the water cycle, states of matter, chemical concentration, energy transfer, energy needs and human impact on climate change.

 

The unit begins with exploring the properties of air and scale and composition of Earth’s atmosphere. You then move into exploring how the movement of air on Earth creates weather and both long and short term predictable events. This is followed by an exploration of seasonal change and the Earth-Sun system. Next you will explore the greenhouse effect and climate change as well as the  human impact in changing Earth’s climate as it is related to our rising energy demands. . The unit ends with an engineering unit exploring wind turbine blade design connected to human energy demands.


Big Ideas

Earth’s Atmosphere

  • Earth has a thin atmosphere that sustains life.
  • Energy from the Sun drives atmospheric processes.
  • Atmospheric circulation transports matter and energy.
  • Earth's atmosphere changes over time and space, giving rise to weather and climate.
  • Earth's atmosphere continuously interacts with the other components of the Earth System.
  • We seek to understand the past, present, and future behavior of Earth's atmosphere through scientific observation and reasoning.
  • Earth's atmosphere and humans are inextricably linked.

 

Matter

  • All things are made of matter, having mass and volume
  • About 100 different elements have been identified, from which all matter (living and nonliving things on Earth) is made.
  • The physical and chemical properties of matter are determined by its composition.
  • Matter and energy cannot be created or destroyed, but they can change from one form to another.
  • Substances can be pure or mixtures
  • The atoms of any element are like other atoms of the same element, but are different from the atoms of other elements. 4D/M1b*
  • Atoms may link together in well-defined molecules, or may be packed together in crystal patterns. Different arrangements of atoms into groups compose all substances and determine the characteristic properties of substances. 4D/M1cd*
  • Atoms and molecules are perpetually in motion.  Increased temperature means greater average energy of motion, so most substances expand when heated, creating changes in pressure and density.  4D/3
  • In solids, the atoms or molecules aer closely locked in position and can only vibrate.  In liquids, they have higher energy, are more loosely connected, and can slide past one another; some molecules may get enough energy to excape into a gas.  In gases, the atoms or molecules have still more energy and are free of one another except during occasional collisions.  4D/3

 

Energy

  • There are a great variety of electromagnetic waves: radio waves, microwaves, infrared waves, visible light, ultraviolet rays, X-rays, and gamma rays. These wavelengths vary from radio waves, the longest, to gamma rays, the shortest. 4F/M8** (BSL)
  • Whenever energy appears in one place, it must have disappeared from another. Whenever energy is lost from somewhere, it must have gone somewhere else. Sometimes when energy appears to be lost, it actually has been transferred to a system that is so large that the effect of the transferred energy is imperceptible. 4E/M1*
  • Energy can be transferred from one system to another (or from a system to its environment) in different ways: 1) thermally, when a warmer object is in contact with a cooler one; 2) mechanically, when two objects push or pull on each other over a distance; 3) electrically, when an electrical source such as a battery or generator is connected in a complete circuit to an electrical device; or 4) by electromagnetic waves. 4E/M2*
  • Thermal energy is transferred through a material by the collisions of atoms within the material. Over time, the thermal energy tends to spread out through a material and from one material to another if they are in contact. Thermal energy can also be transferred by means of currents in air, water, or other fluids. In addition, some thermal energy in all materials is transformed into light energy and radiated into the environment by electromagnetic waves; that light energy can be transformed back into thermal energy when the electromagnetic waves strike another material. As a result, a material tends to cool down unless some other form of energy is converted to thermal energy in the material. 4E/M3*
  •  Energy appears in different forms and can be transformed within a system. Motion energy is associated with the speed of an object. Thermal energy is associated with the temperature of an object. Gravitational energy is associated with the height of an object above a reference point. Elastic energy is associated with the stretching or compressing of an elastic object. Chemical energy is associated with the composition of a substance. Electrical energy is associated with an electric current in a circuit. Light energy is associated with the frequency of electromagnetic waves. 4E/M4*
  • Light and other electromagnetic waves can warm objects. How much an object's temperature increases depends on how intense the light striking its surface is, how long the light shines on the object, and how much of the light is absorbed. 4E/M6**

 

Force and Motion

  • An object’s inertia causes it to continue moving the way it is moving unless it is acted upon by a force to change its motion. (CT)
  • The motion of an object can be described by its position, direction of motion and speed. (CT)
  • The change in motion (direction or speed) of an object is proportional to the applied force and inversely proportional to the mass. 4F/H1*
  • Whenever one thing exerts a force on another, an equal amount of force is exerted back on it. 4F/H4
  • Objects moving in circles must experience force acting toward the center.
  • Energy exists in different forms, and cannot be created or destroyed.
  • In most familiar situations, frictional forces complicate the description of motion, although the basic principles still apply. 4F/H7** (SFAA)
  • If a force acts towards a single center, the object's path may curve into an orbit around the center. 4F/M3b

 

Engineering

  • The Engineering Design Process is an effective tool for solving a variety of engineering problems
  • A system is a group of interacting, interrelated, or interdependent elements forming a complex whole
  • The form of a structure (or its parts) is determined by its function and may be affected by the environment. (For example, the design and materials used in houses throughout the world differs based on the climate & environment.)
  • Materials have different characteristics or properties (e.g., shape, flexibility, texture, color, texture, hardness, color)
  • Objects may be made of different materials depending on the object’s use and the properties required (e.g., strength, hardness, flexibility, etc.)
  •  Strength and stability can be enhanced depending on the way a material is used (e.g., the use of triangles in bridges and skyscrapers)
  • Many variables (materials, forces, earth composition, structural design) determine the stability of a structure.

 

 

Content Learning Expectations

 

Earth’s Atmosphere

  • Create a model of Earth’s atmosphere and explain the properties of each layer
  • Describe how Earth receives energy from the Sun and how it is distributed and cycled through Earth’s systems
  • Use data and maps to explain that weather and climate vary by region based on latitude, altitude, land use, proximity to physical features (e.g., oceans, mountains, ocean currents)
  • Describe how heat is transferred from one object to another by conduction, convection, and/or radiation
  • Use past and present weather data to explain the patterns of circulation in Earth’s atmosphere at many different spacial scales from local to global.
  • Give evidence showing how the spheres of the Earth system (lithosphere, hydrosphere, atmosphere, and biosphere) interact
  • Analyze weather maps and make basic predictions
  • Collect data about Earth’s atmosphere by direct and indirect measurement of temperature, precipitation, wind, pressure and other variables and use the data to formulate a weather forecast
  • Give examples of how living organisms can and do change the composition of Earth’s atmosphere and its processes. Many human activities, such as farming, forestry, building cities, and burning of fossil fuels,  alter atmospheric composition and thereby impact the functioning of ecosystems, human health and climate on local, regional, and global scales.
  • Compare and contrast a range of severe weather phenomena including hurricanes, tornadoes, blizzards, etc.  

 

Matter

  • Give examples to show how the physical characteristics of elements and types of reactions they undergo were used to create the Periodic Table
  • Use the Periodic Table as a tool to predict, compare and contrast compounds and elements
  • Compare and contrast an atom and a molecule (revised MA)
  • Estimate the relative size of particles (atoms) that make up matter and compare to familiar objects or references (e.g., a cell, a millimeter) (MA)
  • Explain that a substance (element or compound) is a sample of matter that has a specific chemical composition and definable properties (such as melting point, boiling point, and conductivity), which are independent of the amount of the sample (MA)
  • Differentiate between mixtures and pure substances (elements and compounds) and between heterogeneous and homogeneous mixtures (MA)
  • Predict properties of matter resulting from physical and chemical changes
  •  Use a particulate model of matter to explain that density is the amount of matter (mass) in a given volume. Measure the mass and volume of an object and calculate its density. (MA)
  •  Demonstrate how the sensitivity of measurement tools (e.g., rulers, graduated cylinders, balances) affect the measurement of volume and mass (MA)
  • Classify substances by their physical properties (MA)
  • Distinguish between physical and chemical changes (MA)
  • Use a particulate model of matter to explain and give examples of how mass is conserved through various transformations of matter (e.g., a phase change) in a closed system (MA)
  • Explain that bonds are forces similar to the force exerted between two magnets, but that there is nothing between particles (MA)
  • Observe and record evidence to show that a chemical change is often accompanied by observable phenomena such as precipitation, gas evolution, change in temperature or change in color (MA)
  • Recognize that in chemical reactions, the atoms present in the reactants are all present in the products, but the atoms are found in different combinations that result in the formation of different substances (MA)
  • Recognize that all chemical changes involve changes in energy (MA)
  • Compare and contrast the properties of common acids and bases (taste, feel, reactivity, and pH)

 

Energy

  • Differentiate between stored energy and energy of motion. Identify situations where energy of motion is transformed into stored energy and vice versa (MA)
  • Collect and anlyze data that shows that adding or taking away heat energy from a system can result in a temperature change (MA)
  • Explain the effect of heat on particle motion through a description of what happens to particles during a change in phase (MA)
  • Present examples of how heat transfers in predictable ways, moving from warmer objects to cooler ones (MA)
  • Identify the basic types of energy (light, sound, thermal, elastic, chemical, electrical, magnetic, gravitational, and kinetic) and relate each to their observable properties (brightness, loudness, temperature and relative strength) (MA)
  • Develop a model demonstrating how energy can be transferred from one object or system to another (or from a system to its environment) in different ways (MA)
  • Explain how heat energy is transferred by convection, conduction and radiation (MA)

 

Force and Motion

  • llustrate how a static object (e.g., table) can exert a force on another object (MA)
  • Measure the mass of an object. Recognize that mass is the amount of matter in an object. Differentiate mass from weight (MA)
  • Predict motion of an object acted upon by multiple push/pull forces
  • Explain and give examples of how the motion of an object can be described by its position, direction of motion, and speed (MA)
  • Describe and diagram the qualitative relationships among force, mass and changes in motion.
  • Draw a force diagram with co-linear forces to determine the net force acting on an object (MA)
  • Explain how a net force resulting from more than one force acting on an object along a straight line may cause a change in the object’s linear momentum (speed or direction). (MA)
  • Create and interpret speed vs. time and position vs. time graphs (MA)
  • Investigate and describe the effects of friction on the motion of objects (MA)
  • Calculate the average speed of a moving object and illustrate the motion of objects in graphs of distance over time.
  • Describe the forces acting on an object moving in a circular path.
  • Use examples of energy transformations from one form to another to explain that energy cannot be created or destroyed.

 

Engineering (Wind Turbines)

  • Complete the engineering design cycle when given specific criteria, materials and constraints
  • Use the design process to evaluate the effect of variables such as blade mass, angle, size, curvature, material, number of blades, area, shape, etc. in solving their problem i.e., producing electricity.
  • Identify evidence of lift and drag forces interacting in the system
  • Identify action-reaction forces.
  • Explain how a wind turbine converts the wind’s mechanical energy into electrical energy.
  • Explain the effect of mass (inertia) on the ability of an object to be accelerated.
  • Measure current and voltage and calculate power
  • Demonstrate the connection between electrical power and mechanical power.
  • Evaluate the use of wind power as one possible source of energy for meeting energy demands in a more sustainable way.
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