Investigate the difference in attractive force between polar and non-polar molecules by 'pulling' apart pairs of molecules. While all molecules are attracted to each other, some attractions are stronger than others. Non-polar molecules are attracted through a London dispersion attraction; polar molecules are attracted through both the London dispersion force and the stronger dipole-dipole attraction. The force of attractions between molecules has consequences for their interactions in physical, chemical and biological applications.
Investigate the difference in attractive force between polar and non-polar molecules by "pulling" apart pairs of molecules. While all molecules are attracted to each other, some attractions are stronger than others. Non-polar molecules are attracted through a London dispersion attraction; polar molecules are attracted through both the London dispersion force and the stronger dipole-dipole attraction. The force of attractions between molecules has consequences for their interactions in physical, chemical and biological applications.
Compare the change in potential energy when you separate molecules from each versus when you break molecules apart.
Before Ernest Rutherford's famous gold foil experiment in 1911, it was not known how the positive part of the atom was distributed. His experiment showed that if you shot positively charged particles at the atoms in a very thin sheet of gold foil, that very rarely, a particle would bounce back from the foil rather than going straight through it. Experiment with changing the distribution of positive charge and see how it affects the paths of positively charged particles moving near it.
The heat conductivity of a solid material defines how fast heat will flow through it. You can probably think of several everyday examples of materials with high (fast) conductivity or low (slow) conductivity. This model illustrates the effect of different conductivities by placing different materials between a hot and a cold object and graphing the changing temperatures.
The rate of heat flow between two objects is proportional to their difference in temperature. One experiences this every day, with stoves, outdoor weather and touching things. If you touch something that's the same temperature as your hand, there's no heat flow at all. This model allows you to adjust the temperature difference between two objects and observe the graph of heat flow.
Heat flows through solids at rates measured by their conductivity. The rate of heat flow is also proportional to the thickness of the material. This model compares the rate of heat transfer between two objects when they are separated by walls of different thickness.
If there are air leaks in a house, you might expect that their effect would be magnified on a windy day. The wind creates greater air pressure on the windward side of the building and forces air in through the leaks. At the same time, the pressure on the other side of the building is lowered, pulling air out through leaks. This model has a fan blowing against a building. Air motion is shown with arrows. Open and close the "windows" in the building and observe the results.
Convection refers to transfer of heat by a fluid material (such as air or water) moving from one place to another. The convection is forced if the fluid motion is caused by a fan or a pump while natural convection is the result of density differences.
Conduction of heat refers to the transfer of heat through a solid. Convection refers to the transfer of heat by a fluid material (such as air or water) moving from one place to another. Warm air is less dense than cold air, so it rises and cold air sinks. This is called natural convection. Air is constantly circulating indoors and outdoors, moving heat from one place to another. With this model you can compare how conduction and convection transfer heat.
The convection of heat in air happens naturally because warmer air is less dense and rises, causing air circulation in many situations. But not always! Air can stratify, with warmer air up high and cooler air down low. With this model you can explore how convection works if the heat source is near the ceiling of a room. You can also compare it to conduction in the same setting.
Air circulates quickly and easily if there are temperature differences to drive its motion. This may be desirable in a room, but in insulated walls and ceilings air circulation is a problem, since it transfers heat. Explore the effect of multiple barriers on the amount of convection and apply this to how insulation should be designed.
Most buildings have leaky places where air can enter or escape -- around windows, ceiling openings like pipes, wires or chimneys, and construction joints such as where the wall meets the floor or the floor rests on the foundation. The size and location of these leaks strongly affects the heating and cooling load. Use this model to experiment with wall and roof leaks in a house with a heater where the air can circulate freely.
Explore how potential energy created by particles of varying charge is converted to thermal energy.
Experiment with a simulated Crookes tube for qualitative results similar to Thomson's experiments in which the electron was discovered.
El módulo de Clima de High-Adventure Science tiene cinco actividades. El módulo explora la pregunta, "¿Cómo será el clima de la Tierra en el futuro?" A través de una serie de preguntas guiadas, explorarás las interacciones entre los factores que afectan el clima de la Tierra. Explora los datos de temperatura de núcleos de hielo, sedimentos y satélites, y los datos de gases de efecto invernadero de las mediciones atmosféricas, realiza experimentos con modelos computacionales y escucha de un científico del clima que trabaja para responder la misma pregunta. No podrás contestar la pregunta al final del módulo, pero podrás explicar cómo los científicos están seguros de que la Tierra se está calentando sin tener la certeza absoluta de cuánto se calentará.
Explore the relationship between the genetic code on the DNA strand and the resulting protein and rudimentary shape it forms. Through models of transcription and translation, you will discover this relationship and the resilience to mutations built into our genetic code. Start by exploring DNA's double helix with an interactive 3D model. Highlight base pairs, look at one or both strands, and turn hydrogen bonds on or off. Next, watch an animation of transcription, which creates RNA from DNA, and translation, which reads the RNA codons to create a protein. Finally, make mutations to DNA and see the effects on the proteins that result. Learn why some mutations change the resulting protein while other mutations are "silent."