The elements beryllium, calcium, and strontium are all in group 2. What is the correct relationship of these elements regarding their ionization energy?
A. [tex]$Ca \ \textless \ Be \ \textless \ Sr$[/tex]
B. [tex]$Sr \ \textless \ Be \ \textless \ Ca$[/tex]
C. [tex]$Be \ \textless \ Ca \ \textless \ Sr$[/tex]
D. [tex]$Sr \ \textless \ Ca \ \textless \ Be$[/tex]
E. [tex]$Ca \ \textless \ Sr \ \textless \ Be$[/tex]
Answer (1)
Ionization energy decreases down a group.
Be is in period 2, Ca is in period 4, and Sr is in period 5.
Therefore, the ionization energy decreases in the order Be > Ca > Sr.
The relationship is S r < C a < B e , so the answer is D. S r < C a < B e
Explanation
Understanding the Problem The problem asks us to determine the relationship between the ionization energies of beryllium (Be), calcium (Ca), and strontium (Sr), which are all in Group 2 of the periodic table. Ionization energy is the energy required to remove an electron from an atom or ion.
Ionization Energy Trend Ionization energy generally decreases as you move down a group in the periodic table because the outermost electrons are farther from the nucleus and are shielded by more inner electrons, making them easier to remove.
Locating the Elements Beryllium (Be) is in period 2, calcium (Ca) is in period 4, and strontium (Sr) is in period 5. Therefore, the ionization energy decreases in the order Be > Ca > Sr.
Determining the Relationship This relationship can be written as Sr < Ca < Be.
Final Answer The correct answer is D. S r < C a < B e
Examples
Understanding ionization energy is crucial in various real-world applications, such as designing solar cells and developing new battery technologies. For example, materials with lower ionization energies are often used in solar cells because they readily release electrons when exposed to light, facilitating the flow of electricity. Similarly, in battery development, the ionization energy of electrode materials affects the battery's voltage and energy density. By carefully selecting elements with specific ionization energies, scientists can optimize the performance of these technologies.
