Problem 83 - Chemistry and Chemical Reactivity

Question

The discovery of two new elements (atomic numbers 113 and 115 ) was announced in February 2004. (a) Use spáf and noble gas notations to give the electron configurations of these two elements. (b) For each of these elements, name another element in the same periodic group. (c) Element 113 was made by firing the nucleus of a light atom at a heavy americium atom. The two nuclei combine to give a nucleus with 113 protons. What light atom was used as a projectile?

Step-by-Step Solution

Answer

(a) Nh: \([Rn] 5f^{14}6d^{10}7s^{2}7p^{1}\); Mc: \([Rn] 5f^{14}6d^{10}7s^{2}7p^{3}\). (b) Nh: Aluminum (Al), Mc: Nitrogen (N). (c) Neon (Ne) was used as the projectile atom.

Step 1: Determine Electron Configuration for Element 113

Element 113 is Nihonium (Nh). The atomic number is 113, indicating it has 113 electrons. The electron configuration in full spáf notation is: \[1s^2 2s^2 2p^6 3s^2 3p^6 4s^2 3d^{10} 4p^6 5s^2 4d^{10} 5p^6 6s^2 4f^{14} 5d^{10} 6p^5 7s^2 6d^{10} 7p^1\]In noble gas notation, it can be represented as: \[[Rn] 5f^{14} 6d^{10} 7s^2 7p^1\]

Step 2: Determine Electron Configuration for Element 115

Element 115 is Moscovium (Mc). The atomic number is 115, indicating it has 115 electrons. The electron configuration in full spáf notation is: \[1s^2 2s^2 2p^6 3s^2 3p^6 4s^2 3d^{10} 4p^6 5s^2 4d^{10} 5p^6 6s^2 4f^{14} 5d^{10} 6p^6 7s^2 5f^{14} 6d^{10} 7p^3\]In noble gas notation, it can be written as:\[[Rn] 5f^{14} 6d^{10} 7s^2 7p^3\]

Step 3: Identify Element in Same Periodic Group for Element 113

Element 113, Nihonium (Nh), is in group 13 of the periodic table. An element in the same group is Aluminum (Al).

Step 4: Identify Element in Same Periodic Group for Element 115

Element 115, Moscovium (Mc), is in group 15 of the periodic table. An element in the same group is Nitrogen (N).

Step 5: Determine the Projectile Atom for Element 113 Creation

To create element 113, a light element with a certain number of protons was fired at a heavy americium atom, which has 95 protons. The projectile was the nucleus of a Neon (Ne) atom, which has 10 protons: 95 (Americium) + 10 (Neon) = 113.

Key Concepts

Nihonium

Nihonium is a synthetic element with the atomic number 113. Discovered relatively recently, it is part of the group 13 in the periodic table, similar to other known elements like Aluminum and Gallium. This group is also known as the Boron group. Nihonium was first synthesized by bombarding Americium with a lighter element. It fits into the broad category of post-transition metals due to its position on the periodic table.

The electron configuration of Nihonium in full notation is:

• 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d¹⁰ 5p⁶ 6s² 4f¹⁴ 5d¹⁰ 6p⁵ 7s² 6d¹⁰ 7p¹

In a more concise form using noble gas notation, it becomes

• [Rn] 5f¹⁴ 6d¹⁰ 7s² 7p¹

The synthesis of Nihonium required precision and advanced technology, reflecting its significance in modern chemistry experimentation. Understanding its electron configuration provides a glimpse into its chemical behavior, helping scientists predict properties and reactions involving this element.

Moscovium

Moscovium, with atomic number 115, is another synthetic element, named after Moscow where it was first synthesized. It conducts itself chemically similar to other elements in group 15, such as Nitrogen and Phosphorus, and is categorized as a pnictogen. Like Nihonium, Moscovium does not occur naturally and was produced by fusing other elements. This involved using a particle accelerator to bombard Americium with Calcium ions, which has 20 protons, intended to create a nucleus containing 115 protons.

The electron configuration for Moscovium is:

• 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d¹⁰ 5p⁶ 6s² 4f¹⁴ 5d¹⁰ 6p⁶ 7s² 5f¹⁴ 6d¹⁰ 7p³

Or using noble gas notation:

• [Rn] 5f¹⁴ 6d¹⁰ 7s² 7p³

Moscovium exemplifies the excitement of chemical exploration and the potential for discovering new trends within the periodic table.

Periodic Table Groups

The periodic table is organized into groups and periods which help categorize elements based on their properties. Groups are the vertical columns, and elements within a group usually share similar chemical properties because they have the same number of valence electrons.

Group 13, where Nihonium is located, is known for metals that form three chemical bonds and includes Aluminum and Gallium. Group 15, where Moscovium belongs, includes elements that form five bonds in compounds, like Nitrogen and Phosphorus. These groups are key to predicting how elements will bond and react chemically.

Understanding the positioning of elements helps reveal periodic trends, such as ionization energy and electronegativity, that govern chemical behavior. Thus, the periodic table not only organizes elements but also aligns them within families that offer insights into their reactivity and role in various chemical processes. As new elements are discovered, they expand our understanding of chemical structures and reactions.