Question

Write the general valence configuration (for example, \(n s^{1}\) for Group 1 ) for the group in which each of the following elements is found. a. barium, \(Z=56\) b. bromine, \(Z=35\) c. tellurium, \(Z=52\) d. potassium, \(Z=19\) e. sulfur, \(Z=16\)

Short answer

The valence electron configurations for the given elements are: a. Barium (Ba) - \(6 s^{2}\) b. Bromine (Br) - \(4 s^{2} 4 p^{5}\) c. Tellurium (Te) - \(5 s^{2} 5 p^{4}\) d. Potassium (K) - \(4 s^{1}\) e. Sulfur (S) - \(3 s^{2} 3 p^{4}\)

Step-by-step solution

Identify the Periodic Group for Each Element

Using the periodic table, identify the group each element belongs to: a. Barium (Ba) - Group 2 b. Bromine (Br) - Group 17 c. Tellurium (Te) - Group 16 d. Potassium (K) - Group 1 e. Sulfur (S) - Group 16

Write the General Electron Configuration for Each Group

Write the general electron configuration for each element's group: a. Group 2 - \(n s^{2}\) b. Group 17 - \(n s^{2} n p^{5}\) c. Group 16 - \(n s^{2} n p^{4}\) d. Group 1 - \(n s^{1}\) e. Group 16 - \(n s^{2} n p^{4}\) (same as tellurium)

Determine the Valence Electron Configuration for Each Element

Now we can write the valence electron configuration for each given element: a. Barium (Ba) - Group 2 - \(6 s^{2}\) b. Bromine (Br) - Group 17 - \(4 s^{2} 4 p^{5}\) c. Tellurium (Te) - Group 16 - \(5 s^{2} 5 p^{4}\) d. Potassium (K) - Group 1 - \(4 s^{1}\) e. Sulfur (S) - Group 16 - \(3 s^{2} 3 p^{4}\)

Key concepts

Periodic Table Groups

The periodic table is meticulously organized into vertical columns known as 'groups' or 'families,' which hold elements with similar chemical properties. This similarity arises because elements in the same group have identical valence electron configurations—the arrangement of electrons in the outermost shell of an atom.

• Group 1 elements have one valence electron, resulting in a configuration of the form: s^{1}.
• Group 2 elements have two valence electrons, thus: s^{2}.
• Groups 13 to 18 follow the pattern: s^2 np^1code>, s^2 np^2code>, up to s^2 np^6code>, respectively, where 'n' represents the period to which an element belongs, and 'p' represents the p orbital electrons.

Identification of an element's group facilitates the prediction of its chemical behavior, reactivity, and bonding with other elements.

General Electron Configuration

General electron configuration provides a framework to understand the distribution of electrons across the orbitals in an atom. These configurations are simplified expressions that reveal the most stable arrangement of electrons, based on the quantum mechanical model of the atom. A typical electron configuration follows the pattern: 1s^2 2s^2 2p^6 3s^2 3p^6, and so on, where the numbers denote the energy levels, 's' and 'p' represent types of orbitals, and exponents denote the number of electrons in those orbitals.

Through electron configurations, we can grasp an element's propensity to lose, gain, or share electrons during chemical reactions, thus better understanding an element's reactivity and bonding nature.

Identifying Periodic Groups

To identify which group an element belongs to, one looks at the number of valence electrons it has. For example, an element with a single valence electron is in Group 1, while those with two valence electrons belong to Group 2. The elements in Groups 13 to 18 have three to eight valence electrons, respectively.

It's important to note that the group number can assist in quickly determining an element's general electron configuration, as seen in the step-by-step solutions provided. Transition metals and inner transition metals have a more complex relationship with their group numbers, often requiring further examination of their electron configurations to understand their chemical behaviors.

Valence Electrons

Valence electrons are the electrons in the outermost shell of an atom, mostly responsible for an atom's chemical properties. Knowing an element's valence electron configuration is like having a key to its chemical behavior, as these electrons are the ones involved in forming chemical bonds. For instance, the Octet Rule states that atoms tend to gain, lose, or share electrons to achieve a full set of eight valence electrons—akin to the configuration of a noble gas.

When solving textbook exercises on this topic, like the given example, it's critical to pinpoint the valence electrons since they're the agents of chemical reactions. Such exercises reinforce the understanding of how group numbers and periods in the periodic table correlate with the number and configuration of valence electrons.