The University of California, Berkeley produced the first synthetic element, called californium (Cf), which is unstable and has a short half different nuclear reaction.
Since the of a second after they are made, fractions with atomic numbers larger than that of uranium have been synthesised.
The synthetic elements have been added to the periodic table.
Californium-252 is bombarded with a nucleus that produces nuclide and six neutrons.
The energy associated with radioactiv ity can ionize.
Problems can develop when radiation ionizes cells.
The radioactivity inside the body can do additional damage, so ingestion of radioactive materials is particularly dangerous.
Acute radiation damage, increased cancer risk, and genetic effects can be divided into three different types.
Nuclear bombs and nuclear reactor cores are the main sources of this kind of exposure.
Rapidly dividing cells, such as those in the immune system, are vulnerable to radiation.
People exposed to high levels of radiation have weakened their immune systems.
Recovery is possible with time in milder cases.
Lower doses of radiation can increase the risk of cancer.
Radiation can damage the cells that carry instructions for cell growth and replication, increasing the risk of cancer.
Normally, the cell's DNA dies in more detail.
Changes in DNA can cause cells to grow.
Cancerous cells can grow into tumors that can cause death.
Increasing radiation exposure increases the risk of cancer.
Determining an exact threshold for increased cancer risk from radiation exposure is difficult because cancer is so prevalent.
Genetic defects in future generations could be a result of radiation exposure.
The offspring of reproductive cells that are damaged by radiation may have genetic defects.
This type has been observed in laboratory animals exposed to high levels of radiation.
Even though there is a connection between radiation exposure and genetic defects, it has not been verified in humans.
There are a number of ways to measure radiation exposure.
A person is bombarded by alpha particles at a rate of 3.8 alpha particles per second.
Different kinds of radiation have different effects.
We know that alpha radiation has more power than beta radiation.
A certain number of alpha decays occurring within a person's body are more damaging than the same number of alpha decays.
The radiation from the alpha emitter is mostly stopped by clothing or the skin because of the low penetrating power of the alpha radiation.
The amount of biological tissue damage caused by the radiation is not an effective measure.
Although these units measure the energy absorbed by bodily tissues, they don't account for the amount of damage caused by that energy absorption, which varies from one type of radiation to another and from one type of biological tissue to another.
The low ion density within the tissue is caused by the energy absorbed being spread out over the long distance that the radiation travels through the body.
When an alpha particle passes through biological tissue, the energy is absorbed over a shorter distance, resulting in a much higher ionization density.
Even though the amount of energy absorbed by the tissue might be the same, the higher ionization density results in greater damage.
The biological effectiveness factor is higher for alpha radiation.
Table 21.4 shows the SI unit that corresponds to natural sources.
The majority of exposure comes from rem.
As we can see from Table 21.4, the rem is still used in most cases, however, some medical procedures also involve exposure levels similar to those received in the United States.
The increased use of computed tomography scans over the factor is 1 rem.
It takes more than the average natural radiation dose or the average dose from a medi cal diagnostic procedure to produce significant health effects in humans.
The first measurable effect is a decrease in the white blood cell count.
Exposures of 100 rem increase the risk of cancer and over 500 rem increases the risk of death.