The two most common isotopes of uranium are 235U and 238U. (b) Using the periodic table in the frontinside cover, write the electron configuration for a U atom.

Verified step by step guidance

1. Identify the atomic number of Uranium (U) from the periodic table, which tells you the number of protons and electrons in a neutral atom.
2. Understand that the electron configuration of an atom describes the distribution of electrons in the atomic orbitals. The configuration is built by adding electrons to the lowest energy orbitals first, following the Aufbau principle, Pauli exclusion principle, and Hund's rule.
3. Start filling the electrons into the orbitals from the lowest energy level to higher, following the order: 1s, 2s, 2p, 3s, 3p, 4s, 3d, 4p, 5s, 4d, 5p, 6s, 4f, 5d, 6p, 7s, 5f.
4. For Uranium, with an atomic number of 92, fill the electrons up to the 7s orbital. Remember that the f-orbitals start filling after the 6s orbital, and the d-orbitals are filled after the corresponding s-orbital except for the first row of the d-block.
5. Write the complete electron configuration by counting the electrons in each subshell until you reach a total of 92 electrons. The configuration will include the filling of the 5f and 6d orbitals.

Key Concepts

Electron Configuration

Electron configuration describes the distribution of electrons in an atom's orbitals. It follows the Aufbau principle, which states that electrons fill the lowest energy orbitals first, and is typically represented using a notation that indicates the energy levels and sublevels occupied by electrons.

Periodic Table

The periodic table organizes elements based on their atomic number and electron configurations. It provides essential information about the elements, including their group and period, which helps predict their chemical behavior and the arrangement of their electrons.

Uranium Isotopes

Uranium has several isotopes, with 235U and 238U being the most common. Isotopes are variants of an element that have the same number of protons but different numbers of neutrons, affecting their nuclear properties but not their electron configuration, which is determined solely by the number of protons.