This set of a teacher and student guides provides instruction on a 2-3 day series of activities about Le Chateliers principle, which shows the effect of changes to conditions in an equilibrium reaction. Students work in pairs or groups to develop their concepts of equilibrium and the effects of changing the amount of reactants or products on an equilibrium system. The concepts are presented and analyzed using graphical representations, qualitative lab data, and modelling. The first part addresses the misconception that equal amounts are required for equilibrium through using a mini-activity that involves the transfer of water between beakers. The second part is a lab activity where students will see how an equilibrium system reacts to a change in concentration. The third part uses manipulatives to understand how an equilibrium operates using the mathematical equilibrium constant (Ksp) at the particulate view.
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This online interactive module of 10 pages or frames integrates textual information, 3D molecular models, interactive molecular simulations, and embedded assessment items to guide students in understanding the copying of DNA base sequences from translation to transcription into proteins within each cell. The module divides the exercises in to Day 1 and Day 2 time frames. Teachers can view student assessment responses by assigning the module within a class created within the Molecular Workbench application. This Java-based module must be downloaded to each computer.
This Java-based NetLogo model allows students to investigate the chemical and energy inputs and outputs of photosynthesis through an interactive simulation. The simulation is a visual, conceptual model of photosynthesis and does not generate quantitative data. The central concept in the model is the role of chlorophyll in capturing light energy, and this concept is presented without delving into the biochemical details of the photosynthetic reactions. This allows students to focus on the core idea that photosynthesis transforms light energy into chemical energy. Along with exploring the basic process of photosynthesis, students can investigate the effects of light intensity, the day-night cycle (assuming the most common C3 photosynthetic pathway), CO2 concentration, and water availability on the rate of sugar production during photosynthesis. The model highlights the cycling within the chloroplasts between excited and unexcited states as energy is captured and released by chlorophyll. The lesson is written as an introductory learning experience, beginning with the question: What is needed for photosynthesis in a leaf, and what is produced? This resource is best suited as one in a series of learning experiences that either reinforce or extend the concepts addressed here. The model is embedded within an electronic form that provides instructions and guiding questions. Teachers and students should note that the electronic form does not save user data. An important limitation is that the model relies heavily on students visual perception, and this may pose a barrier for some students.
An interactive simulation in which students use a model of charged objects to explain how charges interact and construct an understanding of Coulomb's Law. It is concerned with comparing ions and neutral atoms. The model allows the user to investigate the relationships between sign of charge, magnitude of charge, and distance between ions. The model illustrates the operation of three types of electroscopes. Next it visually explores how a static charge can bend the path of a moving electron, and then graphically and numerically explores Coulomb's Law. Lastly a model that illustrates polarization of charge illustrates why a charged balloon is attracted to a neutral wall. The system allows students to enter their multiple choice and written answers throughout the activity and generate a report of their responses at the end even if they are not logged into the system.
In this physics lab, students investigate the motion of different skateboarders pulled with various values of constant force. Using skateboarders of different masses and a variety of constant force values, students produce distance vs. time motion graphs for a number of skateboarding trials. Students may develop their own methods for setting up the lab and recording the necessary data. Following data collection, students analyze the data using Newton's second law and discuss differences between trials, the effects of friction, and possible sources of error in the experiment.
Population Explosion is a computer simulation which allows students to manipulate factors to see what happens over time to a population of sheep within an enclosed field. As the simulation runs, a graph shows the dynamic relationship between the sheep population size and their primary food resource, grass. Students can control factors such as initial number of sheep, grass regrowth rate, gain from food, and birthrate. Predation is represented by a reaper button which may also be controlled. The speed of the simulation can be set so that students can see more clearly what happens over time, or collect data more quickly, depending on how fast the simulation runs. Directions and a suggested simulation sequence are provided along with prompts so that students can pause and consider their results. A space within the simulation is provided for students to record observations and answers to the prompts. For each step in this suggested sequence, students take a snapshot of graphs they have created and store them in an album. At the end of the activity analysis questions help students connect the activity to wild populations. An optional extension exercise is also suggested.
In this activity, the learner explores various ways in which organisms reproduce. The learner discusses the role that reproduction plays in the cycle of life. By watching short videos and participating in follow-up discussion: 1. They observe that no individual organism lives forever and in order to continue species, organisms must pass their genetic instructions on to the next generation. 2. They learn that organisms reproduce asexually, by dividing and producing two identical copies of themselves. 3. They learn that many plants reproduce sexually, often using complex strategies that have evolved over millions of years. 4. They explore the pros and cons of asexual and sexual reproduction and the reasons both strategies persist.
This computer-based learning module engages students in questions that scientists around the world are exploring about Earths climate. They gain an appreciation for how much is not known about the Earth and climate change. The module contains 5 activities; 1) Earths Changing Climates, 2) Interactions Within the Atmosphere, 3) Sources, Sinks, and Feedbacks, 4) Feedbacks of Ice and Clouds, and 5) Using Models to Make Predictions. Each activity provides information in simulations, text, video, or graphic format and the students enter answers to both open-ended and closed questions within the program. Once the students have completed an activity, they can print a report showing all the questions and their answers. The authors estimate the entire module should take 225 minutes.