Experiment with a simulated Crookes tube for qualitative results similar to Thomson's experiments in which the electron was discovered.
This demonstration uses melted phenyl salicylate to show how crystals nucleate and grow as the temperature of the liquid melt decreases.
(Note: this resource was added to OER Commons as part of a batch upload of over 2,200 records. If you notice an issue with the quality of the metadata, please let us know by using the 'report' button and we will flag it for consideration.)
An interactive applet and associated web page that demonstrate the properties of a cube. A 3-D cube is shown in the applet which can be interactively manipulated using the mouse. Research has shown that some younger students have difficulty visualizing the parts of a 3D object that are hidden. To help with this, the student can rotate the cube in any axis simply by dragging it with the mouse. It can also be 'exploded' - where a slider gradually separates the faces to reveal the ones behind. The cube can also be made translucent so you see through it to the other side. Applet can be enlarged to full screen size for use with a classroom projector, and printed to make handouts. This resource is a component of the Math Open Reference Interactive Geometry textbook project at http://www.mathopenref.com.
With your mouse, drag data points and their error bars, and watch the best-fit polynomial curve update instantly. You choose the type of fit: linear, quadratic, cubic, or quartic. The reduced chi-square statistic shows you when the fit is good. Or you can try to find the best fit by manually adjusting fit parameters.
With your mouse, drag data points and their error bars, and watch the best-fit polynomial curve update instantly. You choose the type of fit: linear, quadratic, cubic, or quartic. The reduced chi-square statistic shows you when the fit is good. Or you can try to find the best fit by manually adjusting fit parameters.
DASHlink is a virtual laboratory for scientists and engineers to disseminate results and collaborate on research problems in health management technologies for aeronautics systems. Managed by the Integrated Vehicle Health Management project within NASA's Aviation Safety program, the Web site is designed to be a resource for anyone interested in data mining, IVHM, aeronautics and NASA.
Explore how the code embedded in DNA is translated into a protein. DNA transcription and mRNA translation are modeled.
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.
An elementary review activity for chemistry vocabulary, tools, and concepts used with the classroom science curriculum.
This visualization tool shows sea ice data from 1978 to the present. Selected data can be animated to show changes in sea ice extent over time. Data is added by the National Snow and Ice Data Center as it becomes available.
Simulate the original experiment that proved that electrons can behave as waves. Watch electrons diffract off a crystal of atoms, interfering with themselves to create peaks and troughs of probability.
Explore the effect of an electric field on the electron distribution of an atom.
A demonstration (with full class participation) to illustrate radioactive decay by flipping coins. Shows students visually the concepts of exponential decay, half-life and randomness. Works best in large classes -- the more people, the better.
(Note: this resource was added to OER Commons as part of a batch upload of over 2,200 records. If you notice an issue with the quality of the metadata, please let us know by using the 'report' button and we will flag it for consideration.)
Why do objects like wood float in water? Does it depend on size? Create a custom object to explore the effects of mass and volume on density. Can you discover the relationship? Use the scale to measure the mass of an object, then hold the object under water to measure its volume. Can you identify all the mystery objects?
Why do objects like wood float in water? Does it depend on size? Create a custom object to explore the effects of mass and volume on density. Can you discover the relationship? Use the scale to measure the mass of an object, then hold the object under water to measure its volume. Can you identify all the mystery objects?
Dr. Thomas Hickson (University of St. Thomas) and Karen Campbell (National Center for Earth Surface Dynamics) developed a small, two-dimensional deltaic sedimentation model for the Teaching Sedimentary Geology workshop. This page provides a complete exercise and construction plans to build your own desktop delta.
(Note: this resource was added to OER Commons as part of a batch upload of over 2,200 records. If you notice an issue with the quality of the metadata, please let us know by using the 'report' button and we will flag it for consideration.)
Explore how molecules can cross a cell membrane and learn about the nature of their movement. Set up the model with high oxygen and low carbon dioxide outside the cell and low oxygen and high carbon dioxide inside the cell. In which direction do the oxygen and carbon dioxide molecules move?
Explore the role of pore size in the diffusion of a substance across a membrane. Diffusion is the process of a substance spreading out from its origin. Molecules diffuse through random molecular motion. Diffusion is always happening, even when a system appears to have reached equilibrium, because molecules are always moving. Cells are selectively permeable, meaning that their membranes allow some substances to cross easily while others are unable to cross without assistance. Cell membranes are selectively permeable, in part because its pores are small, allowing the cell to prevent larger molecules from moving across the membrane.
In this interactive demonstration students will make observations of diffusion of a semi permeable membrane and be able to compare these observations to the functions of a cell membrane.
Movement of ions in and out of cells is crucial to maintaining homeostasis within the body and ensuring that biological functions run properly. The natural movement of molecules due to collisions is called diffusion. Several factors affect diffusion rate: concentration, surface area, and molecular pumps. This activity demonstrates diffusion, osmosis, and active transport through 12 interactive models.