Where are expansion cards mounted? What is the easiest way to determine the function of a particular expansion card?

Expansion cards are mounted in expansion slots on the motherboard.

Other than seeing the name written on the card itself, look at the end of the card that fits against the back of the computer case. The port that is connected to the particular expansion card, will be evident to what connects to it.

What is a floppy disk drive (FDD)?

A floppy disk drive (FDD) is an older secondary storage device sometimes found inside a computer. A floppy disk drive can hold 3.5 inch disks containing up to 1.44 MB of data. Floppy disk drives are not as common as they used to be because technology has allowed for storage media that hold much more data, such as CD's, DVD's and USB devices.

Solid State Devices (SSD)

A drive made with flash memory is called a solid state device (SSD). A SSD is a newer technology for hard drives, that use non-volatile flash memory chips, rather than using moving mechanical disks, to hold the data (similar to those used in USB flash drives). Any device that has no moving parts is called solid state.

The two major ATA standards for drive interfaces

Hard drives, CD drives, DVD drives, Zip drives, and tape drives among other devices can use the following interfaces.
serial ATA (SATA), the newer and faster standard and parallel ATA (PATA), the older and slower standard.
The interface between these drives and the motherboard are likely to conform to these standards, published by the American National Standards Institute (ANSI)
SATA cables are flat and thin, one end connects to the device and the other end to the motherboard connector.

PATA is slower than SATA and allows for only two connectors on the motherboard for two data cables. PATA is sometimes called the EIDE (Enhanced IDE) standard or the IDE standard.

The purpose of the computer chipset.

The computers processor could not do its job without the assistance of the chipset. The chipset is a group of microchips on the motherboard that control the flow of data and instructions to and from the processor. The chipset is responsible for the careful timing and coordination of activities. The chipset is contained in two packages embedded on the motherboard.

Three devices that are contained inside the computer case.

The most important component in the case is the central processing unit (CPU), also called the processor or the microprocessor.
The largest and most important circuit board in the computer is the motherboard, also called the main board, the system board. The mother board contains a socket to hold the CPU, where most of the processing takes place.
A power supply with power cords supplying electricity to all devices inside the case.

List and describe the elements that each hardware input, output, or storage device within a computer requires.

Hardware input,output,or storage devices require software to function. Software refers to the set of instructions that directs the hardware to accomplish a task. Software uses hardware for four basic functions:input, processing,storage and output. Also hardware components must communicate both data and instructions among themselves, which requires an electrical system to provide power. Every communication between hardware and software, or between software  and other software is reduced to a simple yes or no, which is represented inside the computer by two simple states: on and off.