Technetium is a radioactive element, with no stable isotopes. With an atomic number of 43, it is the lightest unstable element . ... The short answer is that there is no number of neutrons you can put in a technetium atom to form a stable nucleus.
Why do elements become unstable?
Radiation is emitted from atoms when an unstable atom decays to become more stable. When an atom has extra neutrons or protons , it causes the element to become unstable.
What element is the most unstable?
Characteristics. Francium is one of the most unstable of the naturally occurring elements: its longest-lived isotope, francium-223, has a half-life of only 22 minutes.
Why does technetium 99m undergo radioactive decay?
Technetium-99m decays by a process called isomeric transition, a process in which 99mTc decays to 99Tc via the release of gamma rays and low energy electrons . Since there is no high energy beta emission the radiation dose to the patient is low.
Why are larger elements unstable?
Many of the elements heavier than lead have nuclei so large that they are fairly unstable. Due to the instability, over time they eject a neutron or proton, or a neutron in the nucleus decays into a proton and electron. This is called radioactive decay, since the original nucleus is “decaying” into a more stable one.
What force holds atoms together?
Chemical bonds are forces that hold atoms together to make compounds or molecules. Chemical bonds include covalent, polar covalent, and ionic bonds. Atoms with relatively similar electronegativities share electrons between them and are connected by covalent bonds. ... This attraction is known as an ionic bond.
Why are neutron rich nuclei unstable?
So why is it that increasing a nucleus' size with just neutrons also causes it to become unstable? Additional neutrons are not supplying any additional repulsive forces like protons would, and as far as I know, more nucleons should bring with them more strong force ‘glue' to hold the nucleus together.
Which element is most costly?
The most expensive natural element is francium . Although francium occurs naturally, it decays so quickly that it cannot be collected for use. Only a few atoms of francium have been produced commercially, so if you wanted to produce 100 grams of francium, you could expect to pay a few billion U.S. dollars for it.
Is carbon a stable element?
For example, carbon has six protons and is atomic number 6. ... Carbon-12 is stable , meaning it never undergoes radioactive decay. Carbon-14 is unstable and undergoes radioactive decay with a half-life of about 5,730 years (meaning that half of the material will be gone after 5,730 years).
Why are all elements above 82 unstable?
When the mass number of the atom is greater than 82, the atoms are not stable because of the level of binding energy. The atom splits because of the force of repulsion between the particles and the new elements are formed as they reach the new configuration which is stable. ...
What does TC 99 decay into?
Technetium-99 ( 99 Tc) is an isotope of technetium which decays with a half-life of 211,000 years to stable ruthenium-99 , emitting beta particles, but no gamma rays.
Does the human body use technetium?
Technetium-99m (99mTc) is a radionuclide nuclear agent that is FDA approved for diagnostic imaging of the brain, bone, lungs, kidneys , thyroid, heart, gall bladder, liver, spleen, bone marrow, salivary and lachrymal glands, blood pool, and sentinel nodes.
Why is technetium so weird?
The reason technetium has proved such an unwilling guest is that it is not found in nature . ... Technetium can only be produced artificially because most forms or isotopes of it (atoms of the same chemical element with different numbers of neutrons) have an excess of neutrons, making it very unstable.
Are heavier elements more unstable?
Heavier nuclei are less stable —that's something we all learned in school. Adding more nucleons (protons and neutrons) makes atoms more likely to break apart. It's one reason why elements heavier than plutonium haven't been found in nature.
Can't predict when an unstable nucleus will decay?
Even if a nucleus is unstable, there is no way to tell whether it will decay in the next instant, or in millions of years' time. However, even tiny pieces of material contain very many atoms . ... The half-life of a radioactive isotope is the time taken for half the unstable nuclei in a sample to decay.
Why is a heavy nucleus unstable?
The presence of too many protons and neutrons in heavier nuclei will upset the balance and binding energy of nuclear force , which make the nucleus unstable. Such an unstable nucleus achieves the balance by giving off the neutron and proton via radioactive decay.
