Materials Contributed through SERC-hosted Projects
Determination of Chlorophyll in Olive Oil Using the Vernier Spectrometer part of MnSTEP Teaching Activity Collection:MnSTEP Activity Mini-collection
In this activity, students will investigate how much chlorophyll is in olive oil using a Varnier Spectrometer. Students will measure and analyze the visible light absorbance spectra of three standard olive oils obtained from any supermarket: extra virgin, regular, and light. Students will then measure and determine the absorbance spectrum of an "unknown" olive oil sample. Last, students will determine and identify the "unknown" olive oil sample as one of the three standard types, extra virgin, regular, or light.
HYDROGEN-OXYGEN ROCKETS part of MnSTEP Teaching Activity Collection:MnSTEP Activity Mini-collection
In this chemistry lab, students investigate how to build and launch a simple rocket that uses hydrogen and oxygen gases that will be mixed to propel the rocket (large bulb plastic pipette). Students will understand the principles of combustion reactions, kinetics, stoichiometry of reactions, activation energy, explosive mixtures, rocketry, and different types of chemical reactions. Students will explore and determine the proportions of hydrogen and oxygen mixture that will achieve the best launch results. Students will compare the balanced chemical reaction of hydrogen and oxygen with their lab results; students should discover that the optimal distance occurs when the mixture of hydrogen and oxygen is two to one hydrogen, oxygen mixture ratio and this can be determined theoretically from the balanced chemical reaction equation. Students will perform the lab, collect data, and discuss, compare, and contrast their lab findings with the balanced chemical reaction equation. Students will present their structured inquiry investigations using a power-point presentation. Other groups along with the teacher will assess each group by using a provided rubric. Group assessments will be the deciding assessment for the final lab score. A follow up activity could investigate how NASA scientists launch real rockets into space and propose a procedure to investigate and collect data on a launching a heavier object at the school football field.
Investigating motors and magnetism. part of MnSTEP Teaching Activity Collection:MnSTEP Activity Mini-collection
Students will build a simple DC motor out of metal coat hangers, a 24-guage wire armature and field magnet, 14-guage wire brushes, and build the motor so that it rotates when connected to a 10-volt DC power supply. Students will understand the principles of operation of the DC motor, to include: induction of an electromagnetic field Via current flowing through a conductor (electromagnetism), and become familiar with the notion that Forcetotal of the motor is proportional to charge, proportional to speed, proportional to the induced magnetic field (B), and dependent on the angles between the rotation of the armature in the field magnetism. Forcetotal = qv X B = (mv2/R), where q is the amount of charge, v is velocity of charge, B is the magnetic field strength, m is the mass of the charge, and R is the radius of the armature loop. Students will be able to solve one variable magnetism problems, describe how their motors operate, and write up a lab report on their findings. During the lab report, students will discuss how they got their motors to rotate faster than the initial trial after building it.