1. How do the principles of physics and chemistry both come into play when developing new materials?
Physics describes the behavior of charge, and the sharing or transfer of charged particles (electrons) is responsible for all chemical bonding. Physics is used to describe the physical characteristics of the new material, and physics sets the standards (of strength, density, malleability, etc.) against which the material under development is tested. The principles of chemistry come into play when choosing the elements and compounds used to develop the new material, based on their various chemical properties.

2. How do conductors and insulators differ in their atomic structure?
At the atomic or molecular level, conductors and insulators differ from one another in terms of their ability to allow the flow of charged particles. Conductors allow the flow of charged particles at the atomic or molecular level. This might mean loosely held outer electrons (for metals), but in the case of an electrolyte solution, it means that ions (charged particles) are freely moving through a liquid solution. Insulators do NOT have charged particles that are free to move around.

3. If water in a pipe is analogous to electricity in a wire, what is analogous to a diode? a transistor? What electrical device is analogous to a water storage tank?
A diode is analogous to a check-valve, or one-way valve. A transistor is analogous to a valve in which a diaphragm controls a plunger that affects flow through another section of pipe. A water storage tank, if held at a height, is analogous to a battery. A water storage tank somewhere in the circuit, that needs to be filled before the circuit is completed (e.g., the inflow pipe is at the bottom of the tank, and the outflow pipe is at the top) can be thought of as a capacitor.

4. Why are both insulators and conductors needed in all