4-f series start from

The 4n series starts from Th - 232 and ends at

The 4n series starts from Th-232 and ends at

The 4n series starts from thorium-232 and ends at :

Lanthanide series start from the elements with atomic number

Actinoid series starts from atomic number______________.

Actinoid series starts from atomic number______________.

Two infinite geometric series starts from the same number. If the common ratios are 0.85 and 0.55 respectively, show that the sum of the first series is three times that of the second.

In a series, starting from the second term, if each term its previous term, then the series is in _______ progression.