The beaker tips. The chemicals slosh together in a rainbow of colors. Attentive students peer at the mixture, waiting to see what potion they have come up with.
A routine chemistry experiment? It might be, except this one won't result in any smoke bubbling out of beakers, no nasty chemical vapors, not even a dirty flask. Instead, it will be carried out on a video-display screen; the students won't wear lab coats, but there will be plenty of realism.
The electronic-chemistry lab now being developed by researchers at the University of Nebraska illustrates the potential of an emerging new technology: the interactive videodisc, the union of the computer and the videodisc.
By itself, the computer can produce startling graphics. So, too, can videodiscs flash realistic images on TV screens.
But, by linking the two, even more lifelike images are being created, resulting in a variety of new information tools popping up in classrooms, industrial plants, and shopping malls. What makes this duo versatile is its ability to combine motion-picture video with sound and color - and allow people to ''interact'' with the video screen.
In the case of the electronic-chemistry lab, students will tap commands into a computer keyboard and call up videodisc pictures of a chemical-filled flask. Then, by moving a ''paddle'' on the computer, they will control the ''mixing'' of the solutions. The reaction on the screen will simulate that in a laboratory. To round out the chemistry lesson, written and verbal explanations will be tossed out to the student.
Besides being an effective teaching tool, the interactive system could eventually help schools cut down on outlays for costly chemicals and diminish the potential for accidents in the lab, says Rod Daynes, director of the university's Videodisc Design-Production Group, which is producing the program.
Use of interactive videodisc systems as a teaching and training tool has been around for some time. General Motors, for instance, put them in thousands of automobile showrooms several years ago to teach repair tasks to dealers and flash the latest equipment to customers. Sears, Roebuck & Co. has tested them as electronic salesmen.
But these interactive systems were less sophisticated than some of the new ones being developed. In the computer-videodisc duet, it is the computer that makes the system truly responsive. When a person punches a keyboard or touches a pressure-sensitive screen, the computer retrieves the information. But it is the videodisc that gives the system enough storage capacity to allow moving pictures as well as sound, color, and text to be called up. Here are some of the areas where interactive systems are emerging:
* Industrial training. The military as well as a number of auto, aerospace, and high-technology companies are using or looking at such systems to teach complex repair tasks and train sales personnel. Because the systems combine sound and text with motion-picture demonstrations, they can be an effective (if somewhat costly) alternative to tutoring workers with films or manuals.
Researchers at the Massachusetts Institute of Technology's Architecture Machine Group, for instance, are developing an electronic-repair manual under contract with the Navy. This ''visual toolbox'' takes you step by step through procedures for tackling an automobile transmission.
* Education. Interactive systems are being devised to give students ''hands on'' experience with equipment too expensive for schools to own, such as electron microscopes, or to simulate actual work situations. Others are being used as teaching tools in museums, libraries, and exhibition halls. At the University of Notre Dame, students will sharpen engineering skills by ''running'' a power plant from the classroom. They will call up videodisc pictures, diagrams, and data about the plant by touching a word or symbol on a pressure-sensitive screen. It will also give out detailed explanations and quiz the students on plant operations.
One problem, however, is that budget-pinched schools are hard pressed enough to put computers in the classroom, much less come up with outlays for videodisc players to complete the interactive system. The Yankee Group, a Boston-based marketing-research firm, predicts, nonetheless, that about 18,000 videodisc systems should be in schools by 1990.
* Sales and merchandising. Several computer companies, such as IBM and Apple, are either using or developing interactive programs to help sell equipment at computer outlets. Customers can learn about different models and systems by touching pressure-sensitive screens, which will call up pictures and give demonstrations of the equipment.
Also under development are electronic kiosks. These are small shopping booths or displays that will stand in public places like hotel lobbies. They will provide visual catalogs and handle purchases. Consumers will be able to slip in a credit card and have products delivered to their homes. ''These will be the forerunners of the electronic-catalog store of the future,'' says Harold Bailey, chairman of the New England Technology Group, a Massachusetts-based computer-graphics and videodisc firm working on one of the systems.
Still, use of interactive videodiscs will likely grow slowly. One reason is the lack of disc software for the systems. ''The technology is there, the product is available, but the software simply hasn't been developed yet,'' says Stuart Lipoff of Arthur D. Little Inc., the consulting firm. For the home consumer, the systems hold plenty of potential, but here, too, their popularity will depend on the spread of computers in the home as well as the cost of the videodisc machines.