Question

All the actinoids, atomic number 89 through 103 have seven electron orbits. True False

Answer 1

Answer is: true.
Actinoids are in 7 period in Periodic table and valence orbit is 7s².
Ac - [Rn] 6d¹ 7s².
Th - [Rn] 6d² 7s².
Pa - [Rn] 5f² 6d¹ 7s².
U - [Rn] 5f³ 6d¹ 7s².
Np - [Rn] 5f⁴ 6d¹ 7s².
Pu - [Rn] 5f⁶ 7s².
Am - [Rn] 5f⁷ 7s².
Cm - [Rn] 5f⁷ 6d¹ 7s².
Bk - [Rn] 5f⁹ 7s².
Cf - [Rn] 5f¹⁰ 7s².