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.
How do you know if an element is stable?
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.
How do you know which atom is more stable?
Atoms are at their most stable when their outermost energy level is either empty of electrons or filled with electrons . Sodium atoms have 11 electrons. Two of these are in the lowest energy level, eight are in the second energy level and then one electron is in the third energy level.
How do you determine whether a nucleus is stable or not?
The principal factor for determining whether a nucleus is stable is the neutron to proton ratio
What does it mean when an atom wants to be stable?
Atoms will react to get in the most stable state possible . A complete octet is very stable because all orbitals will be full. Atoms with greater stability have less energy, so a reaction that increases the stability of the atoms will release energy in the form of heat or light.
Why would an atom be unstable?
When the atoms of an element have extra neutrons or protons it creates extra energy in the nucleus and causes the atom to become unbalanced or unstable. Whether radioactive elements
How do you know if a structure is stable?
structure is stable. o If removal of one constraint (a support force or a member force) causes the structure to be unstable (i.e. the structure can be displaced without deforming a member), then the original structure is stable and determinate.
Why is iron nucleus the most stable?
Notice that iron-56 has the most binding energy per nucleon , making it the most stable nucleus. The rationale for this peak in binding energy is the interplay between the coulombic repulsion of the protons in the nucleus, because like charges repel each other, and the strong nuclear force, or strong force.
What is the stability of a nucleus dependent on?
The stability of an atom depends on the ratio of its protons to its neutrons , as well as on whether it contains a “magic number” of neutrons or protons that would represent closed and filled quantum shells. These quantum shells correspond to energy levels within the shell model of the nucleus.
What is the difference between a stable and unstable isotope?
Stable isotopes do not decay into other elements . In contrast, radioactive isotopes
Which elements does not follow the octet rule?
The two elements that most commonly fail to complete an octet are boron and aluminum ; they both readily form compounds in which they have six valence electrons, rather than the usual eight predicted by the octet rule.
What happens when an atom is unstable?
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'. ... If it decays with emission of an alpha or beta particle
What are the exceptions to the octet rule?
However, there are three general exceptions to the octet rule: Molecules, such as NO, with an odd number of electrons ; Molecules in which one or more atoms possess more than eight electrons, such as SF 6 ; and. Molecules such as BCl 3 , in which one or more atoms possess less than eight electrons.
What is the most unstable element?
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. ... A heavy element with a single valence electron, it has the highest equivalent weight of any element.
What causes an atom to be radioactive?
Why Are Some Atoms Radioactive? The delicate balance of forces among particles keeps the nucleus stable . Any change in the number, the arrangement, or the energy of the nucleons can upset this balance and cause the nucleus to become unstable and create a radioactive atom.
What force holds atoms together?
– The basic force that holds all the atoms together in a molecule is known as strong nuclear force
