Which element is represented by the electron configuration [Rn] 7s² 5f¹⁰?

The electron configuration [Rn] 7s² 5f¹⁰ corresponds to the element Californium (Cf). To understand this configuration, it is helpful to break it down.

The notation [Rn] indicates that the configuration includes all the electrons present in Radon, which has the atomic number 86. After Radon, the configuration continues with 7s², indicating that there are two electrons in the 7s subshell. The 5f¹⁰ portion indicates that there are ten electrons in the 5f subshell.

Californium is part of the actinide series, which starts from Actinium (Ac) and includes all the elements up to Lawrencium (Lr), where the 5f subshell is being filled. The atomic number of Californium is 98, which corresponds to the addition of the total number of electrons based on the configuration: 86 from Radon, 2 from the 7s², and 10 from the 5f¹⁰.

Thus, when you add these, 86 + 2 + 10 equals 98, confirming that the electron configuration corresponds specifically to Californium.

Other elements