The \[^{14}S{i_{28}}\] and \[^{14}S{i_{29}}\] are called_________?

Hint: In order to deal with this question first we will understand the terms ISOBARS and Isotopes.
Which are important for naming the chemical element for their chemical composition.

Complete answer:
The \[^{14}S{i_{28}}\] and \[^{14}S{i_{29}}\] are called isotopes. Isotopes are the atoms of the same element having the same atomic number but different mass numbers. Here silicon has the same atomic number of 14 and variable mass number of 28 and 29. Three stable isotopes of silicon are known: silicon-28, which makes up \[92.21\] percent of the element in nature; silicon-29, \[4.70\] per cent; and silicon-30, \[3.09\] per cent.
Even though they all have the same atomic number, careful experimental examination of naturally occurring samples of several pure elements shows that not all the atoms present have the same atomic weight. This is only possible if the atoms have different numbers of neutrons in their nuclei. Such groups of atoms have similar atomic numbers but differ in relative weight are called isotopes.
A naturally occurring element's number of isotopic forms can range from one (for example, fluorine) to as many as ten (for example, tin); many elements have at least two isotopes. In most cases, an element's atomic weight can be calculated from many atoms containing the natural distribution of isotopes, and it thus represents the atoms' average isotopic weight The sample is made up of a certain amount of weight. Precision mass-spectrometric methods have recently been used to determine the weights and distributions of isotopes in various naturally occurring element samples.

Note:
The relative numbers of atoms of various elements are commonly referred to as the elements' abundances. Observations of the chemical composition of gas clouds in the Galaxy are the primary sources of data from which information on current-day abundances of elements is obtained.