Answer:
The traditional unit of radiation quantity exposure is known as the roentgen (R). It is a unit used to measure the amount of ionizing radiation that is absorbed by air. The roentgen is defined as the amount of radiation that produces one electrostatic unit of charge (esu) in one cubic centimeter of dry air at standard temperature and pressure.
Step-by-step explanation:
The roentgen was first introduced by Wilhelm Conrad Roentgen, a German physicist who discovered X-rays in 1895. He named the unit after himself to honor his groundbreaking discovery. The roentgen was widely used in the early days of radiation measurement and continues to be used in some applications today, although it has been largely replaced by more modern units.
To understand how the roentgen is measured, it is important to know that ionizing radiation consists of charged particles or electromagnetic waves that have enough energy to remove tightly bound electrons from atoms, creating ions. When ionizing radiation passes through air, it ionizes the molecules in the air, creating positive and negative charges. The roentgen measures the number of ion pairs produced per unit mass of air.
In practical terms, the roentgen can be measured using a device called an ionization chamber. This chamber contains a gas, typically air or a mixture of gases, and two electrodes. When ionizing radiation passes through the chamber, it ionizes the gas molecules, creating a current between the electrodes. The magnitude of this current is proportional to the amount of radiation exposure and can be used to determine the roentgen value.
It is important to note that the roentgen measures only the amount of radiation absorbed by air and does not directly measure the biological effects of radiation on living organisms. Different types of radiation have different biological effects, even if they have the same roentgen value. Therefore, other units such as the rad (radiation absorbed dose) or rem (roentgen equivalent man) are used to measure the biological effects of radiation.
In conclusion, the traditional unit of radiation quantity exposure is the roentgen (R). It measures the amount of ionizing radiation absorbed by air and was named after Wilhelm Conrad Roentgen, the discoverer of X-rays. While it is still used in some applications, it has been largely replaced by more modern units such as the rad or rem for measuring the biological effects of radiation.