Problem 43 - Chemistry The Molecular Science

Question

In 1998 , researchers in Dubna, Russia, synthesized element 112 , copernicium, by reaction of uranium- 238 nuclei with calcium- 48 nuclei. The copernicium- 283 isotope was produced along with neutrons. Write a balanced nuclear equation to represent this synthesis.

Step-by-Step Solution

Answer

The equation is: \(_{92}^{238}\text{U} + _{20}^{48}\text{Ca} \rightarrow _{112}^{283}\text{Cn} + 3\cdot{_{0}^{1}\text{n}}\).

Step 1: Identify the Reactants and Products

The reactants are uranium-238 (\(_{92}^{238}\text{U}\)) and calcium-48 (\(_{20}^{48}\text{Ca}\)). The products are copernicium-283 (\(_{112}^{283}\text{Cn}\)) and one neutron (\(_{0}^{1}\text{n}\)).

Step 2: Set Up the Equation

Write the nuclear equation using the identified reactants and products:\(_{92}^{238}\text{U} + _{20}^{48}\text{Ca} \rightarrow _{112}^{283}\text{Cn} + x\cdot{_{0}^{1}\text{n}}\).

Step 3: Balance Proton Numbers

The total number of protons before and after the reaction must be the same. Reactants: \(92 + 20 = 112\), which matches the 112 protons of copernicium. This is balanced.

Step 4: Balance Mass Numbers

The total mass number before and after must also be the same. Total mass number of reactants: \(238 + 48 = 286\). Total mass number of products: \(283 + 1 \cdot x = 283 + x\). To balance, \(286 = 283 + x\). Solve for \(x\):\[x = 286 - 283 = 3\].

Step 5: Write the Balanced Equation

The balanced nuclear equation is:\[_{92}^{238}\text{U} + _{20}^{48}\text{Ca} \rightarrow _{112}^{283}\text{Cn} + 3\cdot{_{0}^{1}\text{n}}\].

Key Concepts

Nuclear Equations

Nuclear equations are vital for understanding reactions occurring within atomic nuclei. Unlike chemical equations, where the focus is on the electrons, nuclear equations deal with changes in the atom's nucleus. The process of balancing these equations ensures the conservation of both mass and atomic numbers.
When creating a nuclear equation, identify the reactants and products first. Each element is represented by its chemical symbol, atomic number (number of protons), and mass number (total number of protons and neutrons).
In our example, the nuclear equation involves:

• Uranium-238, represented as \(_{92}^{238}\text{U}\)
• Calcium-48, represented as \(_{20}^{48}\text{Ca}\)
• Copernicium-283, represented as \(_{112}^{283}\text{Cn}\)
• Neutrons, represented as \(_{0}^{1}\text{n}\)

The equation is balanced when the sum of atomic numbers and the sum of mass numbers are equal on both sides. In this scenario, the reactants sum to 286 in mass numbers and 112 in atomic numbers, matching the products with the addition of three neutrons.

Element Synthesis

Element synthesis refers to the creation of new elements, primarily through nuclear reactions. This is a field of great interest in nuclear chemistry. Synthetic elements are not found naturally on Earth and are typically produced in laboratories under controlled conditions.
The synthesis process generally involves bombarding a heavy element with a lighter one—often using particles like protons, neutrons, or ions. In our specific case, Copernicium was synthesized by colliding uranium-238 with calcium-48. This method allows the nuclei of the two elements to merge, forming a new, heavier element.
Key points in element synthesis include:

• Selection of target and projectile elements (like uranium and calcium).
• Precise control of collision conditions to reach the energy required for fusion.
• Detection and identification of the produced isotope, in this case, Copernicium-283.

This field not only answers fundamental questions about the building blocks of matter but also expands the periodic table, providing new possibilities in materials science and other disciplines.

Copernicium

Copernicium is a synthetic element with the symbol Cn and atomic number 112. First synthesized in 1998, it honors the astronomer Nicolaus Copernicus. As a superheavy element, it belongs to the group of transuranium elements that are beyond uranium on the periodic table.
Copernicium is not found in nature due to its high instability and radioactivity. The isotope Copernicium-283, produced in the Dubna experiment, had an extremely short half-life of about 240 microseconds. These characteristics make it interesting for study but challenging to work with.
Useful details about Copernicium include:

• It likely behaves similar to other group 12 elements, such as zinc, cadmium, and mercury.
• Its chemical and physical properties are primarily predicted through computational chemistry.
• Research continues to understand Copernicium's properties and potential uses, though its instability limits practical applications.

The discovery of Copernicium demonstrates the capabilities of advanced technology and international collaboration in modern scientific research.