The SI units of energy are Joules but the effects of ionizing radiation are rarely described only by the energy. The pertinent quantities are the activity (number of decays per second), the does (energy deposited per unit mass) and the equivalent dose, a related measure which takes into account the biological effect of exposure on tissues.
The SI units for these quantities are the Becquerel, the Gray and the Seivert. The equivalent units of radiation still in use in the United States are Curie, the Rad and the Rem.
The Curie or Becquerel is a measure of the ability of a source to produce ionizing radiation measured in the number of decays per second. The Becquerel is equal to one decay per second. A Curie on the other hand is equal to 3.7 x 1010 Becquerels.
The Grey is a measure of the energy deposited per kilogram of matter and dependent not only on the number of decays per second but also on the distance to the source and on the ability of any particular type of ionizing radiation to interact with matter. A Grey has units of Joules per Kilogram (100 Rad is equal to 1 Grey). The Grey does not attempt to take into account the biological damage done to different tissues.
The Seivert (or rem) is the equivalent dose or the product of the radiation intensity (Grey) and factors which attempt to account for the biological damage done to different tissues by different types of ionizing radiation. While the Sievert has the same base units as the Grey (Joules per Kilogram) they are applied differently and named separately to avoid confusion.
kilowatt-hour (kWh)
Radiation absorbed dose (rad) is a unit used to quantify the amount of energy absorbed from ionizing radiation by a material or tissue. It is defined as the energy deposited by ionizing radiation per unit mass of the absorbing material.
Hello W/m2 is not the unit of energy. Students get confused usually as we use the symbol E for the energy radiated per unit area per second. So it is not only the energy. It is the energy emitted in one second. So J/s which equals to W. Per unit area needs /m2 So W/m2 is not the unit for energy. Only J ie joule is the unit of energy.
A rad is a unit of absorbed radiation dose, but it is not commonly used anymore. The International System of Units now uses the gray (Gy) as the standard unit for absorbed radiation dose. 1 rad is equal to 0.01 gray.
No, the calorie is an older unit. The SI unit is the Joule.
While the SI unit - and therefore, the recommended unit - for energy is the joule, energy used in households is more commonly measured in kWh. Since a joule is a watt-second, a kWh (kilowatt-hour) is equal to 3,600,000 joules.
kilowatt-hour (kWh)
Radiation absorbed dose (rad) is a unit used to quantify the amount of energy absorbed from ionizing radiation by a material or tissue. It is defined as the energy deposited by ionizing radiation per unit mass of the absorbing material.
One energy unit starting with C is a calorie, which is a unit of energy commonly used in nutrition to measure the energy content of food. Another energy unit is a coulomb, which measures electrical charge.
Hello W/m2 is not the unit of energy. Students get confused usually as we use the symbol E for the energy radiated per unit area per second. So it is not only the energy. It is the energy emitted in one second. So J/s which equals to W. Per unit area needs /m2 So W/m2 is not the unit for energy. Only J ie joule is the unit of energy.
The Rad is a unit of ionizing radiation, measuring its energy distribution in air. A Rontgen is similar, but it measures the energy absorbed by an object. A REM is a Rontgen Equivalent Man, so it measures the energy absorbed by a human being.
A photon is a particle of electromagnetic radiation with no mass that carries a quantum of energy. It is the fundamental unit of light and other forms of electromagnetic radiation.
A unit of absorbed energy from ionising radiation equal to one thousand grays. A gray (Gy) is the SI unit of absorbed radiation dose of ionising radiation, defined as the absorption of one joule of ionising radiation by one kilogram of matter (usually human tissue).
A rad is a unit of absorbed radiation dose, but it is not commonly used anymore. The International System of Units now uses the gray (Gy) as the standard unit for absorbed radiation dose. 1 rad is equal to 0.01 gray.
No, the calorie is an older unit. The SI unit is the Joule.
A photon is a fundamental particle that doesn't consist of smaller components. It is a packet of energy that carries electromagnetic radiation and is considered as the most basic unit of light.
The unit of energy commonly used to identify the amount of energy released or absorbed by a chemical reaction is the kilojoule (kJ).