<h2>IM SORRY I CAN'T UNDERSTAND YOUR QUESTION PLEASE TRY AGAIN PLEASE DONT REPORTED MY ANSWER THIS IS FOR MY FAMILY MY SARV AND SELEVER</h2>
I am pretty sure it is d if i am wrong please tell me
Answer:
All atoms heavier than barium
Explanation:
In the periodic table, elements are divided into blocks. We have the;
s- block elements
p- block elements
d- block elements
f- block elements
However, immediately after Barium, we now encounter elements that have f-orbitals. Barium possesses a fully filled d-orbital. Hence after it, we see elements with 4f and 5f orbitals called the Lanthanides and actinides. The elements following the lanthanide and actinide series possess completely filled f-orbitals as inner orbitals.
Hence elements heavier than barium all possess f-orbitals.
