Problem 51 - Chemistry and Chemical Reactivity

Question

The superheavy element \(^{287} \mathrm{Fl}\) (element 114 ) was made by firing a beam of \(^{48}\) Ca ions at \(^{242}\) Pu. Three neutrons were ejected in the reaction. Write a balanced nuclear equation for the synthesis of \(^{287} \mathrm{Fl}\).

Step-by-Step Solution

Answer

The balanced equation is \( ^{48}_{20}\mathrm{Ca} + ^{242}_{94}\mathrm{Pu} \rightarrow ^{287}_{114}\mathrm{Fl} + 3^1_0\mathrm{n} \).

Step 1: Identify Reactants and Products

The reactants in the nuclear reaction are the calcium isotope \(^{48}\)Ca and the plutonium isotope \(^{242}\)Pu. The product of the reaction is the superheavy element flerovium \(^{287}\)Fl. Additionally, three neutrons (\(^1_0n\)) are ejected as part of this reaction.

Step 2: Write the Nuclear Reaction

In a nuclear reaction, the sum of the mass numbers and the atomic numbers needs to be conserved. The equation for the reaction can be written as follows: \[ ^{48}_{20}\mathrm{Ca} + ^{242}_{94}\mathrm{Pu} \rightarrow ^{287}_{114}\mathrm{Fl} + 3^1_0\mathrm{n} \]

Step 3: Verify Mass and Atomic Number Conservation

Check the conservation of mass numbers and atomic numbers on both sides of the equation:- The sum of mass numbers on the left is \(48 + 242 = 290\) and on the right is \(287 + (3 \times 1) = 290\).- The sum of atomic numbers on the left is \(20 + 94 = 114\) and on the right is \(114 + 0 = 114\).This confirms both mass and atomic number conservation in the balanced equation.

Key Concepts

Superheavy Elements

Superheavy elements are fascinating substances that reside at the far edge of the periodic table. These elements, like flerovium (Fl), are not naturally occurring and are produced through complex nuclear reactions. Flerovium, also known as element 114, was first synthesized by scientists who aimed to discover new elements by colliding smaller atomic nuclei together. This process involves using heavy ion beams, such as calcium ions, to bombard target materials like plutonium. The result is the creation of elements that possess incredibly high atomic numbers.

Creating superheavy elements is complex due to their instability. They often exist for very short periods before decaying into other elements. Despite their fleeting nature, studying these elements helps scientists understand the forces that bind atomic nuclei and explore theoretical predictions about the "island of stability," where certain superheavy isotopes might have relatively longer lifetimes.

Nuclear Reactions

Nuclear reactions involve changes in the nucleus of atoms, different from chemical reactions which involve electrons. In nuclear reactions, elements can transform into different elements, as seen in the synthesis of superheavy elements like flerovium (Fl).

During these reactions, the atomic nuclei collide and combine to form a new nucleus. In the reaction involving calcium-48 ions and plutonium-242, the nuclei fused to form flerovium-287. This process typically requires careful control of the reaction environment to achieve.

At the heart of nuclear reactions are key principles such as conservation laws. In our example, it's crucial to control the reaction energy and particle velocities to manage the formation of desired elements efficiently without unnecessary byproducts.

Mass Number Conservation

Mass number conservation is a fundamental principle in nuclear chemistry. It states that the sum of mass numbers (protons plus neutrons) in the reactants must equal the sum in the products in a nuclear reaction.

In the synthesis of flerovium-287 ( Fl ), the mass numbers add up perfectly: the calcium-48 and plutonium-242 react to give flerovium-287 and three neutrons. Here's how it works:

• The sum of the mass numbers of reactants: 48 (from Ca) + 242 (from Pu) = 290.
• The sum of the mass numbers of products: 287 (from Fl) + 3 (from three neutrons each having a mass number of 1) = 290.

This confirms the conservation of mass numbers. Similarly, atomic number conservation is also crucial to ensure that the sum of atomic numbers remains constant during the nuclear reaction. This symmetry helps verify the feasibility and success of the equation.