Assertion :The last element in a group is radioactive. Reason: In case of elements with high atomic masses, nucleus is unstable.
Assertion :The last element in a group is radioactive. Reason: In case of elements with high atomic masses, nucleus is unstable.
The correct option is B Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion
There are two rows under the periodic table: the lanthanide and actinide series. The lanthanide series can be found naturally on Earth. Only one element in the series is radioactive. The actinide series is much different. They are all radioactive and some are not found in nature.
The force that binds the positive protons in a nuclei is the strong force, same as the force that binds quarks together to form neutrons and protons. The strong force operates at a very close range only, about 1−3 femtometers. As the atomic number increases, and protons and neutrons are forced together, the effectiveness of the strong nuclear force decreased as particles are further away from each other, and electrostatic force of repulsion takes over. So for elements of high atomic number, their nuclei can be very unstable and are susceptible to the process of nuclear fission.
There are two rows under the periodic table: the lanthanide and actinide series. The lanthanide series can be found naturally on Earth. Only one element in the series is radioactive. The actinide series is much different. They are all radioactive and some are not found in nature.
The force that binds the positive protons in a nuclei is the strong force, same as the force that binds quarks together to form neutrons and protons. The strong force operates at a very close range only, about 1−3 femtometers. As the atomic number increases, and protons and neutrons are forced together, the effectiveness of the strong nuclear force decreased as particles are further away from each other, and electrostatic force of repulsion takes over. So for elements of high atomic number, their nuclei can be very unstable and are susceptible to the process of nuclear fission.
