Which doubly positive ion has the ground-state electron configuration 1s2 2s2 2p6?

Name: Chemistry
Author: McMurry
ISBN: 9781292336145

Verified step by step guidance

Step 1: Identify the given electron configuration: 1s^2 2s^2 2p^6. This configuration represents a total of 10 electrons.

Step 2: Recognize that the configuration 1s^2 2s^2 2p^6 corresponds to the noble gas neon (Ne), which has 10 electrons in its neutral state.

Step 3: Since the problem asks for a doubly positive ion, consider that the ion has lost 2 electrons from its neutral state.

Step 4: Determine the neutral atom that, when it loses 2 electrons, results in the electron configuration of neon. This would be an atom with 12 electrons in its neutral state.

Step 5: Identify the element with 12 electrons in its neutral state, which is magnesium (Mg). Therefore, the doubly positive ion is Mg^{2+} with the electron configuration 1s^2 2s^2 2p^6.

Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Electron Configuration

Electron configuration describes the distribution of electrons in an atom's orbitals. It is represented by a series of numbers and letters indicating the energy levels and types of orbitals occupied by electrons. For example, the configuration 1s2 2s2 2p6 indicates that there are two electrons in the 1s orbital, two in the 2s orbital, and six in the 2p orbital, filling the first and second energy levels.

Ionic Charge

Ionic charge refers to the net electrical charge of an ion, which occurs when an atom gains or loses electrons. A doubly positive ion, or cation, has lost two electrons, resulting in a charge of +2. Understanding how the loss of electrons affects the electron configuration is crucial for identifying the corresponding ion.

Noble Gas Configuration

Noble gas configuration is a shorthand notation for electron configurations that reflects the stable electron arrangement of noble gases. The configuration 1s2 2s2 2p6 corresponds to the electron configuration of neon, a noble gas. This stability is often a reference point for determining the electron configurations of ions, as ions tend to achieve a noble gas configuration to attain stability.