# Individual Hardware Store Science Experiments

Hardware Store Science includes 28 individual modules addressing all of the topics typically covered in a high school physical science course.  A teacher can select individual topics to use in their current courses or they can use the complete suite of experiments for a full two semester physical science course.

## Organization of Science Experiment Modules.

Physical science is typically taught as a collection of disconnected topics, i.e. simple machines, potential and kinetic energy, chemical reaction, electric circuits, etc.  However, there are some basic principles that underlie all of the physical science. These principles can effectively organize the various topics so they logically build upon each other.  This is the approach that has been used to organize the topics in the suite of Hardware Store Science experiments.  The teacher can use the experiments in any order that they find useful, but we believe there is an order that is most natural.

Physical science is organized around fundamental conservation principles:  conservation of mass, conservation of energy, and conservation of momentum.

• Conservation of mass is a key idea in chemical reactions, where the mass of the reactants equals the mass of the products although the reactant and product molecules are different.
• Conservation of energy is the key principle behind a projectile where kinetic energy is converted into potential energy.   Also, the 1st law of thermodynamics is conservation of energy.
• Conservation of linear momentum is Newton’s 2nd law, i.e. F=ma.  A more precise statement of Newton’s 2nd law is the rate of change of momentum equals the sum of all forces, where for an object with constant mass Newton 2nd law simplifies to F=ma..

Although these conservation principles are often not clearly covered in most high school physical science textbooks (these conservation principles are often reserved for an AP Physics course), we believe they are extremely useful in designing the organization of a general physical science course.

Section A, B, C and D in the curriculum are concerned with mechanics and are organized around the three conservation principles described above.  Sections E and F are concerned with chemistry, starting with properties of gases, then introducing chemical reactions and finally including phase changes like melting.  Basic electricity is introduced in Section G that includes the behavior of simple electrical components like resistors and capacitor, followed by experiments on more complex devices like electromagnets and motors.  Finally, in Section H the basic principles of optics are introduced.  The traditional way to teach a general physical science course is to start with the physics of mechanical world (i.e. Sections A through D) and then progress through chemistry (Sections E and F), electricity (Section G) and finally optics (Section H). Hardware Store Science materials have been written so the various sections can be rearranged to meet the needs of different instructors.

The 30 experiments in Section A through G are under development.  A number of the experimental modules are complete, but others are under development.  A complete list is provided in order to show that when completed, the Hardware Store Science modules will cover all of the topics in a general physical science course.

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