Question

In the general electronic configuration,
$(n-2)f^{1-14}(n-1)d^{01}n{s}^2$ (where n = 7) the configuration will be of:

• A. lanthenides
• B. actinides
• C. transition elements
• D. none

Answer 1

The correct option is B actinides

General electronic configuration is given:

$(n-2)f^{1-14}(n-1)d^{01}n{s}^2,where(n=7)$
$5f^{1-14}6d^{01}n{s}^2$
The seventh period $(n=7)$ is similar to the sixth period with the successive filling up of the 7s, 5f, 6d and 7p orbitals and includes most of the man-made radioactive elements. This period will end at the element with atomic number 118 which would belong to the noble gas family. Filling up of the 5f orbitals after actinium $(Z=89)$ gives the 5f-inner transition series known as the Actinoid Series.