Interactive simulations in Physics and Chemistry

Chemistry is a practical science but also with a lot of abstract concepts which students find hard to understand, such as atomic structure, bond formation, isotopes, gas properties, photoelectric effect, etc...
For this reason, interactive programs are very useful to explain these concepts, so students can see it in a very attractive way.


All of the simulations are very useful, but if I had to choose some of them, this would be my selection:

• Build a molecule: Starting from atoms, you can see how many molecules you can build, and you can see them in 3D! It is good, because blackboards only have 2D. It's very accurate for students of third course at Secondary School as a first approach to the concept of molecule and its structure http://phet.colorado.edu/en/simulation/build-a-molecule

• Atomic interactions: Good way to explain the graphic that shows the variation of potential energy with the distances between atoms. http://phet.colorado.edu/en/simulation/atomic-interactions
• Isotopes and Atomic Equations: To catch the idea of isotopes as different atoms of the same element you can use this simulation in which you'll see how many protons, electrons and neutrons a the atoms can have. http://phet.colorado.edu/en/simulation/isotopes-and-atomic-mass
• Balancing chemical reactions: After the explanation of the Law of Conservation of Mass, students should know how to apply it to balance a chemical reaction. Some of them find it difficult because they don't catch the relation between the atomic mass and the number of atoms both sides of the equation. http://phet.colorado.edu/en/simulation/balancing-chemical-equations