Question

In which atomic orbital(s) to the alkaline earth elements contain valence electrons? 1\. \(s\) 2\. \(d\) 3\. \(s\) and \(d\) 4\. \(\quad s, d\), and \(p\)

Short answer

1. \(s\)

Step-by-step solution

Identify the electron configuration of alkaline earth elements

As alkaline earth metals belong to group 2 of the periodic table, their general electron configuration is: \[ [X]ns^2 \] Where [X] represents the noble gas core and n is the principal energy level of the valence electrons.

Determine the atomic orbital(s) for valence electrons

Since the valence electrons exist in the s orbital (ns^2), the corresponding atomic orbital for alkaline earth metals' valence electrons is "s."

Select the correct option

Based on the above information, the valence electrons of alkaline earth elements are found in the s orbital. Therefore, the correct answer is: 1. s

Key concepts

Electronic Configuration

Understanding the electronic configuration of an element is crucial for grasping many aspects of its chemical behavior. Electronic configuration refers to the arrangement of electrons in the atomic orbitals of an atom. Electrons fill atomic orbitals in a way that minimizes the energy of the atom, following specific rules such as the Aufbau principle, Pauli exclusion principle, and Hund's rule.

For the alkaline earth elements, which sit in Group 2 of the periodic table, the electronic configuration can be succinctly represented as \[ [X]ns^2 \], where \(n\) stands for the principal quantum number that corresponds to the energy level the valence electrons are in, and \(s\) signifies that these valence electrons are located in the s orbital. The notation \([X]\) represents the core electrons, which are configured like the nearest noble gas preceding the element in the periodic table.

This configuration indicates that alkaline earth elements have two valence electrons, both of which are in the s orbital of the outermost energy level. Understanding this pattern helps in predicting and explaining the element's chemical reactivity, bonding properties, and placement in the periodic table.

Atomic Orbitals

Diving deeper into the concept of atomic orbitals helps in visualizing where electrons reside within an atom. Orbitals are regions within an atom where the probability of finding an electron is highest. The s, p, d, and f orbitals have different shapes and energies, and can each hold a specific number of electrons: s can hold 2, p can hold 6, d can hold 10, and f can hold 14.

For the alkaline earth elements, their valence electrons are in the s orbital, which is spherical in shape and surrounds the nucleus of the atom. Since these orbitals can hold up to two electrons, they are completely filled in alkaline earth elements, giving them a stable electron configuration. This full s orbital is significant in determining the elements' behavior in reactions, such as their tendency to lose two electrons to achieve a noble gas configuration.

Periodic Table Group 2

Group 2 of the periodic table is known as the alkaline earth metals group. These elements share similar properties due to their identical valence electron configuration — specifically, they all have two electrons in the outermost s subshell. Starting with beryllium (Be) and including magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), and radium (Ra), these elements are characterized by their silvery color, their metallic properties, and being less reactive than their alkali metals counterparts in Group 1.

Due to having two valence electrons, alkaline earth metals typically form +2 cations and are commonly found in compounds such as oxides, hydroxides, and carbonates. These elements play significant roles in biological systems, industrial applications, and are also important for human nutrition.