This applet adds relevance to the equilibrium portion of the course and provides an interesting problem-solving activity. To get to the top of the mountain before winter arrives, students must derive an equation that relates the necessary amount of hemoglobin to the partial pressure of oxygen at the current and next camp. Everest connects a paper and pencil calculation to a computer simulation of a real-world phenomenon. The calculation is challenging, but is similar to those that the students often solve in the equilibrium part of the course. The applet illustrates the use of computer simulation to allow students to interact with a complex phenomena, at an earlier point in a course than would otherwise be possible. For instance, the Everest applet involves a kinetic phenomenon: the body responds to a decrease in the amount of atmospheric oxygen by growing more hemoglobin. Nevertheless, the problem is presented in such a way that students need only understand the chemical equilibrium of a single chemical reaction. The kinetic aspects of the system are handled by the simulation; the student need only wait until the amount of hemoglobin produced by the body is sufficient to survive at the next elevation. Everest also implements a simple approach to automatic grading. When a student successfully climbs the mountain, the applet sends an email (containing an encrypted key word) to the teacher indicating that the student has completed the assignment.
In this activity, students will hook up a hair to a lever system and create a hair hygrometer to measure changes in humidity. Invented in 1783, the hair hygrometer was so reliable that it was not replaced by an electrical instrument until the 1960s.
Sensibilisation des étudiants au problème des déchets engendrés par les activités de laboratoire et d'atelier des lycées et lycées professionnels.
In this interactive object, learners review descriptions of various blood collection tube additives. They then test their knowledge by matching the different tubes to their corresponding additives. Resource from Wisc-Online : free access but sign-in is mandatory.
With Identification of Chemical Bonds II, students write electron configurations of ground-state atoms, analyze formulas, build basic units, bond basic units, and analyze the substance corresponding to different chemical formulas. Then, in a computer lab, they receive a sheet at random containing two chemical formulas for which they must complete all the previously learned steps and print the report.
As homework, students must build the Lewis structures for six chemical formulas, analyze them, and do the 3-D drawings. Next, in a computer lab, students in pairs use the Lewis Structures II application to check their answers and view their molecules or ions in 3-D. Students are strongly encouraged to return to the lab on their own or purchase the software in order to practise with the greatest possible number of chemical formulas.
Researchers, looking for intriguing interactions between cells and small molecules, use techniques to expose large numbers of diverse compounds to treated cells. This 3D animation illustrates one of these techniques. In this example, the objective is to screen small molecules for ones that interact with the glucose sensing protein network. Each well in the 384-well plate contains a small number of cells. The cells have been put into a “diabetic-like” state through the use of the small molecule rapamycin.
This resource was designed to introduce students to research sources in the field of chemistry. Students can find direct links to primary sources or information about locations where the materials can be found (there are also a number of exercises that allow students to test their own knowledge about chemistry resources at Columbia University).
Le but de ce film est de visualiser les trajectoires d'une molécule de méthane adsorbée dans une cavité de la zéolithe NaA (maille élémentaire (SiO2AlO2)12Na12). Ces trajectoires ont été calculées pas à pas par une simulation numérique de la dynamique translationnelle de CH4 à partir d'un potentiel d'interaction de la molécule avec les ions du cristal, en fonction de l'énergie du système. Le pas du mouvement est de 5.10 -15 s et le nombre de pas de 50 000.GénériqueRéalisateur : Alexis Martinet Conseillers scientfiques : E. Cohen de Lara, A.M. Goulay, R. Kahn, M. Le Bars Producteur : Institut de cinématographie scientifique, CNRS-Audiovisuel (CNRS Images) et DRP (Université Paris VI) Distributeur : ICS (ics@cnrs-bellevue.fr) et CNRS (http://www.cnrs.fr/diffusion) Année de production : 1990 Titre original : Dynamics of a molecule in a cage
Ce vidéo film est une étude de la distribution électronique dans divers oxydes dans lesquels l'oxygène est dans son état d'ionisation O2-. Pour chaque composé, on visualise 2 fois 2 types de représentations des densités différences, par rapport à un modèle uniquement composé d'atomes sphériques. A partir des études des cristaux, NiO, CoO et MnO, pour NiO, les ions Ni2+ et O2- forment leurs propres cages. Pour CoO, les déformations électroniques, autour de O2- , sont dues aux formations des liaisons entre les cages de O2- et le cation. Dans MnO, ces mêmes déformations sont moins prononcées. Pour les oxydes cubiques MgO, CaO, SrO et BaO, les déformations de O2- rendent l'ion complètement isolé du cation, amenant un caractère croissant de liaison ionique, depuis MgO jusqu'à BaO. L'étude de BeO montre que les distributions électroniques des ions O2- construisent des filets alternés-plans, de maille hexagonale. Des ponts, entre les différents niveaux des plans, enchâssent les ions Be2+ dans le réseau des O2-. Les cations jouent simplement le rôle d'agents électrostatiques stabilisants.
This work by La Vitrine Technologie-Éducation is licensed under a Creative Commons Attribution-Noncommercial-Share Alike 2.5 Canada License.