Problem 7 - Chemistry and Chemical Reactivity

Question

Use noble gas and spdf notations to depict electron configurations for the following metals of the third transition series. (a) Tantalum, Ta. The metal and its alloys resist corrosion and are often used in surgical and dental tools. (b) Platinum, Pt. This metal was used by pre-Columbian Indians in jewelry. It is used now in jewelry and for anticancer drugs and industrial catalysts.

Step-by-Step Solution

Answer

Ta: \\[ \text{[Xe]} 6s^2 4f^{14} 5d^3 \\] Pt: \\[ \text{[Xe]} 6s^1 4f^{14} 5d^9 \\]

Step 1: Understand the Periodic Table

To find the electron configuration of Tantalum (Ta) and Platinum (Pt), we first locate them on the periodic table. Tantalum is element number 73, and Platinum is element number 78. Both are in the sixth period and part of the d-block, known as transition metals.

Step 2: Identify the Noble Gas Preceding Each Element

Tantalum (Ta) is in the sixth period. We use Xenon (Xe) as the preceding noble gas (element 54). For Platinum (Pt), the preceding noble gas is also Xenon (Xe).

Step 3: Build the Electron Configuration Using Noble Gas Notation

For Tantalum (Ta): Start with the noble gas Xenon (Xe), then add electrons for the 6s, 4f, and 5d subshells. For Platinum (Pt): Begin with Xenon (Xe), similar to Tantalum's steps but extend the arrangement to fill more of the 5d subshell.

Step 4: Electron Configuration for Tantalum (Ta)

Within the 6th period for Tantalum: after Xenon, fill the 6s subshell (2 electrons), the 4f subshell (14 electrons), and finally place 3 electrons in the 5d subshell. Therefore, Ta: \[ \text{Ta}: [\text{Xe}] 6s^2 4f^{14} 5d^3 \].

Step 5: Electron Configuration for Platinum (Pt)

For Platinum: after Xenon, fill the 6s subshell (2 electrons), add all 14 electrons to the 4f subshell, and add 9 electrons to the 5d subshell. Therefore, Pt: \[ \text{Pt}: [\text{Xe}] 6s^1 4f^{14} 5d^9 \]

Step 6: Repeat and Verify

Ensure configurations respect electron filling order and Hund's rule, adjusting as necessary for electron stability in transition metals.

Key Concepts

Noble Gas Notation

Noble gas notation is a simplified way of writing electron configurations that helps to make them easier to read and understand. Instead of writing out every single electron configuration from scratch, we can start from the last noble gas encountered in the periodic table.
This method is especially helpful for elements with many electrons like transition metals.

For example, consider Tantalum (Ta) and Platinum (Pt) from the third transition series. Both elements have complex electron structures because they have many electrons. By using the noble gas notation, we start with Xenon \[Xe\], the noble gas that comes before them in the periodic table.

• For Tantalum: \[ \text{[Xe]} \ 6s^2 \ 4f^{14} \ 5d^3\]
• For Platinum: \[ \text{[Xe]} \ 6s^1 \ 4f^{14} \ 5d^9\]

This method saves time and space and provides a clear starting point for more detailed electron configuration.

Transition Metals

Transition metals are fascinating elements often found in the middle of the periodic table within groups 3 to 12. They are unique due to their partially filled d subshells. This gives them special properties, such as the ability to form multiple oxidation states, and being good conductors of heat and electricity.

Both Tantalum (Ta) and Platinum (Pt) are part of the transition metals. These elements often form colored compounds and are frequently used in industry due to their complex chemistry.

• They can exhibit a wide range of chemical properties.
• Their electrons usually come from both the s and d subshells when forming ions.

These characteristics make them particularly useful in various applications, including jewelry and industrial catalysis.

D-block Elements

The d-block elements occupy the central part of the periodic table and include elements where the last electron enters the d subshell. When chemists refer to these elements, they often speak of the transition metals, which are renowned for their versatile chemistry.

Within d-block elements like Tantalum and Platinum, electrons are added to the 5d subshell as we move across the periodic table from left to right. These elements tend to have high melting and boiling points and are characterized by their metal properties.

In their electron configurations, electrons from the s and d subshells play crucial roles in defining their chemical bonding and properties. Because of these unique properties, d-block elements are indispensable in technologies ranging from electronics to catalysis in emissions control.

Third Transition Series

The third transition series, often called the 5d series, includes heavier transition metals that appear in the 5d block of the periodic table. These metals, like Tantalum (Ta) and Platinum (Pt), exhibit periodic properties that are more intense and complex due to the higher principal quantum number.

Electrons are filled in the order dictated by the periodic table, addressing subshells in a sequence that stabilizes the atom.

• Electrons for these elements begin filling from the 6s, then 4f, followed by the 5d subshells.
• This electron fill order is important for understanding chemical reactions and compounds involving these elements.

These transitions series elements are crucial in industrial applications for their strength and stability, resistance to corrosion, and catalytic capabilities. Such properties demonstrate their vital role not only in science but also in everyday technology and medicine.