Isotopes are a different version of atoms in a chemical element. These atoms have nuclei with varying number of neutrons, but the same number of protons. The atomic mass of each of the isotopes is different, making them physically different from each other.
Most natural elements have isotopes that are stable in their behavior. Elements can also have radioactive or unstable isotopes. Usually, for a given element, isotopes have equal number of protons and electrons and display similar chemical behavior due to a similar electronic structure.
Read on to understand the isotope terms better.
Atom
An atom is the smallest, indivisible unit of an element that retains the properties of the element. It contains a positively charged nucleus and negatively charged electrons that orbit around it.
Radioisotopes or radioactive isotopes
In an unstable atom, the nucleus keeps changing, becomes radioactive and remits alpha, beta or gamma rays until it can achieve stability. These become radioactive isotopes.
Kinetic isotope effect
The kinetic isotope effect or isotope fractionation refers to the dependency of the rate of a chemical reaction on the isotopic identity of an atom.
Neutrons
Neutrons make up the nucleus of an atom along with protons. They stick together due to a strong nuclear force. Free neutrons are radioactive and they have no electrical charge.
Protons
Protons are within an atom's nucleus along with neutrons. Protons have a positive electric charge and are generally stable. Quarks are smaller particles that form protons.
Windows to the Universe, a scientific and educational website at the University Corporation for Atmospheric Research (UCAR).
Electrons
Atoms consist of the nucleus and electrons. Electrons usually have a negative charge, but some positrons or positively charged electrons exist. Within an atom, electrons can have differing energy levels and depending on that, they absorb or emit photons.
