Magnesium has three naturally occurring isotopes. The most common, magnesium-24, accounts for nearly 80% of the magnesium found in nature. The atomic numbers and mass numbers for four different atoms are shown in the table below. Which of these atoms could be an isotope of magnesium?

Answer : There are mainly three isotopes of magnesium found in nature; namely Mg-24, Mg-25 and Mg-26. Out of which Mg-24 has 12 neutrons, Mg-25 has 13 neutrons and Mg-26 has 14 neutrons in their atoms. The number of protons and their atomic masses remains the same for the atom. The relative abundance in nature differs for all the three isotopes. Mg-24 has abundance nearly 80% in nature, Mg-25 has abundance as 10% and Mg-26 has 11.01% abundance.