Final answer:
IR sample plates are made out of potassium bromide (KBr) because it is transparent to infrared radiation, allowing for minimal interference during infrared spectroscopy.
Step-by-step explanation:
The student's question asks which material is used to manufacture IR (infrared spectroscopy) sample plates. In this context, potassium bromide (KBr) is the correct answer. Laboratory IR samples require a material that is transparent to infrared radiation; KBr is ideal for this purpose because unlike materials such as plastic, glass, or quartz, it allows the IR radiation to pass through without significant absorption. Therefore, the SAIR sample plates are commonly made out of potassium bromide (KBr).