Problem 54 - Chemistry Matter and Change

Question

Bone Formation The electron capture of strontium-85 can be used by physicians to study bone formation. Write a balanced nuclear equation for this reaction.

Step-by-Step Solution

Answer

The balanced nuclear equation is: \( ^{85}_{38} \text{Sr} + ^{0}_{-1} \text{e}^- \rightarrow ^{85}_{37} \text{Rb} \).

Step 1: Identify the Nuclide Undergoing Electron Capture

We're given that the nuclide undergoing electron capture is strontium-85, denoted as \( ^{85}_{38} \text{Sr} \). This isotope has an atomic number \( Z = 38 \) and a mass number \( A = 85 \).

Step 2: Understand Electron Capture

In electron capture, an inner orbital electron is captured by the nucleus of its own atom, leading to the conversion of a proton into a neutron. This reduces the atomic number by 1, but does not change the mass number.

Step 3: Identify the Product of Electron Capture

When strontium-85 undergoes electron capture, a proton is converted into a neutron. Thus, the new element formed will have one less proton. The atomic number changes from 38 to 37, producing rubidium-85 \( ^{85}_{37} \text{Rb} \).

Step 4: Write the Balanced Nuclear Equation

The balanced nuclear equation for the electron capture of strontium-85 is:\[ ^{85}_{38} \text{Sr} + ^{0}_{-1} \text{e}^- \rightarrow ^{85}_{37} \text{Rb} \]

Key Concepts

Electron Capture

Electron capture is a fascinating process in nuclear physics. During electron capture, an electron from an atom's inner shell is drawn into the nucleus where it combines with a proton. This changes the proton into a neutron, effectively transforming the element into a different isotope or even a completely new element. The atomic number decreases by one, but the mass number stays the same since only the balance between protons and neutrons is affected.

Consider the case of strontium-85. When this isotope undergoes electron capture, the interaction results in the formation of a different atom. The process can be understood by looking into how the structure of the atom is modified, driven by this subatomic interaction.

• The captured electron transforms a proton to a neutron.
• The atomic number of the element reduces by 1, reflecting the reduction in the proton count.
• There is no change to the mass number since both protons and neutrons contribute equally to it.

The simplicity yet profundity of this transformation underscores the delicate balance and powerful dynamics within atomic nuclei.

Strontium-85

Strontium-85 is a notable isotope of strontium, characterized by its atomic number 38 and mass number 85. This means it has 38 protons and 47 neutrons. Strontium itself is an element often found in fireworks, known for its vivid red flame color. However, in scientific contexts like nuclear medicine, isotopes such as strontium-85 hold significant value.

This particular isotope can be used to study various biological processes, such as bone formation. Its behavior during electron capture is of particular interest in understanding the structural changes within bones as it effectively changes to rubidium-85 post-reaction. Some notable attributes include:

• It is a beta-emitter, which contributes to its applications in medical imaging.
• Its transformation results in rubidium-85, aiding in safer biological applications.
• Key to research in diagnostic and therapeutic medicine.

Strontium-85's ability to undergo electron capture and thus become another element makes it a critical tool in both practical applications and theoretical explorations in nuclear science.

Rubidium-85

Rubidium-85, resulting from electron capture of strontium-85, is a stable isotope of rubidium. As a product of this nuclear reaction, rubidium-85 has 37 protons and maintains the same mass number of 85 due to its identical neutron count with its precursor. The transition from strontium to rubidium doesn’t affect the overall atomic mass, yet it illustrates a subtle yet significant nature of nuclear transformations.

Rubidium itself is a soft, silvery-white metallic element of the alkali metal group. In its isotope form, rubidium-85 provides depth to the study of nuclear reactions because:

• It remains stable, providing a comparative stable end-product post-reaction.
• Its properties help analyze electron capture effects on nuclear scale.
• Rubidium-85's predictability offers a valuable identity in the vast atomic landscape.

Understanding its characteristics helps reveal the intricacies of electron capture, enhancing our comprehension of atomic behavior under nuclear reactions.

Proton to Neutron Conversion

The proton to neutron conversion is a core aspect of nuclear transformations involving electron capture. This process is crucial for determining the outcome of elements during nuclear reactions. When a proton turns into a neutron, the balance of charge within the nucleus shifts, thus resulting in a new element with different properties.

In the context of our example with strontium-85, the process works as follows:

• Electron capture initiates the conversion by introducing an inner electron into the nucleus.
• The interaction of this electron with a proton converts it into a neutron.
• This conversion decreases the atomic number by one, but the mass number remains unchanged as neutrons contribute equally to the mass along with protons.

Such conversions are fundamental to many nuclear processes beyond electron capture, highlighting their importance in both practical applications and fundamental physics research. These reactions help scientists explore the deeper structures of particles and anticipate other nuclear interactions.