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 I isotopes of silicon are known: silicon-28, which makes up 92.21 per cent of the element in nature; silicon-29, 4.70 per cent; and silicon-30, 3.09 per cent.
