Lead
The periodic table is an important tool in the field of chemistry, as well as a systematic chemical guide, where we can find the atomic number and atomic weight of each element, and where they are classified, and at the same time, this classification mechanism also helps us understand some of the properties and characteristics between the elements.
In the periodic table, the elements are arranged in the order of increasing atomic number, and at the same time, they also show a certain periodicity and regularity, so that people can more easily classify and study the elements.
In this table, there are also some elements that humans have not yet been able to observe in natural conditions, such as the element in the 43rd place, technetium, which was not known to us until scientists found its traces in the laboratory environment through isotopic concepts.
So why is technetium, element 43, so rare, and what are the properties and characteristics of this element?
And why is technetium so easy to prepare in the laboratory?
1. "I can't find it when I look for it."
First, let's take a look at some basic things to know about element 43 – technetium.
We know that every element in the periodic table is assigned to a certain group of elements according to its atomic number and some specific properties, such as alkali metals, alkaline earth metals, halogens, and so on.
Technetium, on the other hand, is a transition metal element, and not only that, but it is also a radioactive element, and its radioactivity is also an important clue to its discovery.
In the periodic table, the technetium element is placed in the 43rd position, and its atomic number is 43, according to the property distribution law of the periodic table, we know that the electronic configuration of the technetium element is: K2, L8, M18, N13, O2.
So, how can we infer more information about the properties of technetium based on this property?
In terms of properties, technetium and its adjacent elements, namely molybdenum in group 21 of element 42 and ruthenium in group 22 of element 44, have similar properties.
Molybdenum and ruthenium are both transition metal elements, and the oxidation states in their compounds are +6, +5 and +4 respectively, so according to this law, the oxidation states in technetium compounds should be in the range of +5 or +4.
In nature, technetium is also extremely rare, but its rarity is also relative, in fact, the content of technetium in stars such as red giants is still relatively abundant, and it is even called "technetium star".
Second, the source of technetium.
In the past, scientists have been exploring and studying the process of element generation and evolution in the universe through astronomical observations and theoretical research, and in these studies, they have also discovered some new and interesting phenomena.
Technetium is a relatively common element in the universe, and in the core of red giants and other stars, gravity leads to the fusion of prime nuclei that promotes the production of more elements, including technetium.
In this high-temperature and high-pressure environment, the content of technetium is relatively abundant, and it has become an important radiating element, so the name technetium star also comes from the phenomenon of relatively abundant technetium.
As for the specific source of technetium, after a series of studies and calculations, scientists found that technetium is produced by stable molybdenum through neutron bombardment, and there is no stable technetium isotope in nature.
When neutrons interact with molybdenum nuclei, there is a certain probability that the nucleus of molybdenum will be damaged, resulting in a stable technetium nucleus, the atomic number of molybdenum is 42, and the atomic number of technetium is 43.
The combination of neutrons and molybdenum nuclei is originally an unstable state, so after the formation of technetium nuclei, a series of decay reactions will occur in a very short period of time, including radiation reactions, thus releasing a certain amount of radiation energy, which is regarded as an important clue to the existence of technetium.
We know that molybdenum is a relatively common element in nature, therefore, the production of technetium will be affected by a certain natural environment, such as the natural environmental conditions on the earth are unfavorable for the interaction between neutrons and molybdenum, and even neutron phagocytosis will occur.
The natural environmental conditions on the earth are more favorable for the production of technetium, but despite this, there are still no human beings who have been able to find minerals containing technetium in the natural environment, which also brings a deeper mystery to the rarity of technetium.
However, through laboratory research, scientists have found that compounds containing technetium can be prepared by carrying out reactions such as mixing of some isotopes and bombardment of neutrons in an experimental environment.
3. Isotopes of the technetium element.
We know that technetium is a very precious element, and its isotopes are also very valuable, because due to the rarity of technetium, its isotopes are also very difficult to prepare in the laboratory, so it has a very important value.
Isotopes refer to elements with the same atomic number, but different numbers of protons and neutrons, and between these different isotopes, there are often some similar or different atomic properties.
There are a total of 24 isotopes of technetium, of which 21 isotopes are unstable, and after a period of time, a decay reaction will occur, and one of the isotopes has a relatively long decay half-life, which can reach 6 billion years, and this isotope can exist for a long time.
The other two isotopes have very short decay half-lives of 53 days and 6 hours, respectively, which is an important indicator of technetium and the reason why it is found in the natural environment.
In the earth's natural environment, the influence of electromagnetic waves such as gamma rays will lead to the decay reaction of the technetium nucleus, resulting in a radiant reaction, which is the key clue that scientists have found when observing minerals containing technetium in the earth's natural environment.
In the core region of the red giant, the temperature is as high as 30 million degrees, and this high temperature environment is very favorable for the nuclear fusion reaction of the elements, and because of the high probability of the nuclear fusion reaction of technetium, the content of the red giant is relatively rich.
Through the understanding of the distribution and characteristics of technetium in nature, it is not difficult to find that although the content of technetium in the earth's natural environment is extremely rare, it can be easily prepared by artificial means in the laboratory environment, which also makes the application of technetium more extensive.
Fourth, the application of technetium.
Technetium has a wide range of applications in both medical and industrial applications, one of the most important of which is in medical imaging.
In the field of modern medicine, for some major or rare diseases, it is necessary to have a comprehensive understanding and examination of the patient's physical condition, so as to carry out a reasonable treatment plan for the patient.
In medical imaging diagnosis, doctors can use X-rays to have a preliminary understanding of the patient's bone structure and muscles, but for some small organs or cell structures, they cannot make a detailed diagnosis, so it is often necessary to examine the patient through MRI and other equipment.
The magnetic resonance equipment uses the radioactivity of technetium to detect, because technetium is a radioactive element, it will continuously release a certain amount of radiation energy, which is the key to the detection of nuclear magnetic resonance equipment.
When a doctor injects a compound containing technetium into a patient's body, technetium continuously releases radiation energy, and at the same time, MRI equipment can measure and analyze the radiation of the patient, so as to obtain detailed information about the patient's body.
At the same time, another important application of technetium is in the measurement of fuel consumption of nuclear power plants, nuclear power plants, as a clean energy power generation equipment, have always been an important tool for human beings to solve the problem of energy crisis.
The principle that nuclear power plants can generate electricity is generated by nuclear fission reactions, which generate heat to drive steam turbines to start generating electricity, and nuclear fission reactions are generated by the interaction of neutrons with uranium, but over time, the nuclear fuel in the nuclear power plant will continue to decay, so it is necessary to monitor the burn-up in the nuclear power plant.
In this process, the burn-up is determined by artificially creating technetium, and scientists will use specific neutrons to bombard uranium nuclei through experiments, so as to produce compounds containing technetium, which can be used as an important clue for radiation measurements in nuclear power plants.
V. Conclusion
Technetium, as a rare element, is also a precious element, and human research and exploration of it will never stop.
At the same time, scientists are also synthesizing some rare elements, such as uranium, which can not only meet the needs of industry and medicine, but also provide an important way to explore more unknown elements.
In addition, the study of synthetic elements can also help us understand the characteristics of elements, so that the elements can be reasonably prepared in the laboratory, which provides an important reference for future element exploration and research.
At the same time, the abundant content of technetium in the universe also provides us with important clues, which are of great significance for the generation and evolution of the universe.