What causes the nucleus of an atom isotope to become unstable?

An atom is stable if the forces among the particles that makeup the nucleus are balanced. An atom is unstable (radioactive) if these forces are unbalanced; if the nucleus has an excess of internal energy. Instability of an atom’s nucleus may result from an excess of either neutrons or protons.

Why are nuclei with more than 83 protons unstable?

They are unstable because they have too much energy, too many protons, or an unstable ratio of protons to neutrons. For example, all elements with more than 83 protons—such as uranium, radium, and polonium—have unstable nuclei. The nuclei of these elements must lose protons to become more stable.

What is the breakdown of the nucleus of an unstable atom called?

As the unstable nucleus attempts to become stable, it emits radiation and changes into a different element as the number of protons changes. This process is called radioactive decay and it continues until the forces in the nucleus are balanced and stable.

Can you make a radioactive isotope unstable stable?

Most isotopes become stable by emitting alpha particles, beta particles, positrons, or gamma rays. A few become stable by electron capture or by spontaneous fission. GAMMA RAYS: Gamma rays are high-energy photons.

Why are some isotopes stable and others unstable?

Atoms of the same element with different numbers of neutrons are called isotopes. A: The nucleus may be unstable because it has too many protons or an unstable ratio of protons to neutrons. For a nucleus with a small number of protons to be stable, the ratio of protons to neutrons should be 1:1.

Why even even nuclei are more stable?

Nuclides containing even numbers of both protons and neutrons are most stable and this means less radioactive. than nuclides containing even numbers of protons and odd numbers of neutrons. In general, nuclear stability is greater for nuclides containing even numbers of protons and neutrons or both.

Which of the following nuclei would be the most stable?

Nickel-62 is an isotope of nickel having 28 protons and 34 neutrons. It is a stable isotope, with the highest binding energy per nucleon of any known nuclide (8.7945 MeV).

Why are larger atoms unstable?

Bigger atoms are more unstable because there is less nuclear charge on the valence electrons and so, it becomes easy for the valence electrons to come of their shell.

How do unstable atoms gain stability?

Unstable systems gain stability by losing energy. Unstable nuclei lose energy by emitting radiation in a spontaneous process called radioactive decay.

What is unstable atom?

An unstable atom has excess internal energy, with the result that the nucleus can undergo a spontaneous change towards a more stable form. This is called ‘radioactive decay’. Each element exists in the form of atoms with several different sized nuclei, called isotopes.

What is an unstable radioactive isotope?

Radioisotopes are radioactive isotopes of an element. They can also be defined as atoms that contain an unstable combination of neutrons and protons, or excess energy in their nucleus.

Why is the nucleus unstable when there are more protons?

The nucleus is unstable if the neutron-proton ratio is less than 1:1 or greater than 1.5. At close distances, a strong nuclear force exists between nucleons. This attractive force comes from the neutrons. More protons in the nucleus need more neutrons to bind the nucleus together.

What happens when an unstable atom becomes radioactive?

In an unstable atom, the nucleus changes by giving off a neutron to get back to a balanced state. As the unstable nucleus changes, it gives off radiation and is said to be radioactive. Radioactive isotopes are often called radioisotopes.

What happens if an atom has more than one neutron?

Even if an atom has an additional neutron or two it may remain stable. However, an additional neutron or two may upset the binding energy and cause the atom to become unstable. In an unstable atom, the nucleus changes by giving off a neutron to get back to a balanced state.

How does the number of neutrons affect the strength of nuclear force?

At close distances, a strong nuclear force exists between nucleons. This attractive force comes from the neutrons. More protons in the nucleus need more neutrons to bind the nucleus together. The graph below is a plot of the number of neutrons versus the number of protons in various stable isotopes.