Question

Lanthanoids are placed in
a) 3rd group and 7th period
b) 3rd group and 6th period
c) 4th group and 7th period
d) 3rd group and 5th period

Answer 1

The reason why Lanthanides and Actinides are located at the bottom of the periodical table is because of their properties and in the block in which electrons fill up. The lanthanides include elements 58 to 71 (fill out the 4f subshell) and the actinides include elements 89 to 103 (fill out the 5f subshell).Mar 29, 2018