Question

Isotopes occupy the same ______ in the periodic table.

Answer 1

• Atomic number(Z)- The total number of protons in the nucleus of an atom gives us the atomic number of that atom.
• Mass number(A)- The number of protons and neutrons combine to give us the mass number of an atom.
• Isotopes- Atoms of an element having the same atomic number but a different mass number are known as isotopes.
• Example- Hydrogen has three isotopes namely hydrogen, deuterium, and tritium.
• Hydrogen has 1 proton, Z=1, A=1.
• Deuterium has 1 proton and 1 neutron, Z=1, A=2.
• Tritium atom has 1 proton and 2 neutrons, Z=1, A=3.
• In these atoms atomic number is 1 while the mass number is changing.
• Hence, these atoms are examples of isotopes of Hydrogen.
• Since the periodic table is arranged on the basis of the atomic number of elements, the atomic number does not change for isotopes, and nor does their place change in the periodic table.

Isotopes occupy the same place in the periodic table.