Question

You read the following statement about two elements \(\mathrm{X}\) and \(\mathrm{Y} :\) One of the elements is a good conductor of electricity, and the other is a semiconductor. Experiments show that the first ionization energy of \(\mathrm{X}\) is twice as great as that of Y. Which element has the greater metallic character?

Short answer

The element with the greater metallic character is Y because it has a lower ionization energy than X, as represented by the relationship \(IE(X) = 2 \cdot IE(Y)\). Elements with lower ionization energies have a higher metallic character as they can more easily lose electrons.

Step-by-step solution

Analyze the ionization energies of X and Y

We are given that the first ionization energy of X is twice as great as that of Y. This means that X requires more energy to lose an electron than Y. Mathematically, we can represent this relationship as follows: \(IE(X) = 2 \cdot IE(Y)\)

Compare the metallic character of X and Y

Since elements with lower ionization energies have a higher metallic character, we can compare the ionization energies of X and Y to determine which element has the greater metallic character. From step 1, we can see that the ionization energy of Y is less than the ionization energy of X since \(IE(X) = 2 \cdot IE(Y)\).

Identify which element has the greater metallic character

Since Y has a lower ionization energy than X, it can more easily lose an electron and has a greater metallic character. So, the element with the greater metallic character is Y.

Key concepts

Ionization Energy

Ionization energy is a fundamental concept in chemistry that refers to the amount of energy required to remove the most loosely held electron from an atom in its gaseous state. This property is intrinsically linked to the metallic character of an element. Generally, metals have lower ionization energies compared to non-metals because their outermost electrons are more loosely held, allowing them to be easily removed.

In the case of elements X and Y from the given exercise, element Y has a lower ionization energy, suggesting that it's easier for Y to lose an electron and form a positive ion. This characteristic is typical of a metal. Understanding the relationship between ionization energy and metallic character is essential, as it helps in predicting the reactivity and bonding behavior of elements within the periodic table.

Semiconductor

Semiconductors occupy a middle ground between conductors and insulators. They are materials with electrical conductivity less than that of a conductor but more than that of an insulator. One of the hallmark properties of semiconductors is their ability to change conductivity with the addition of impurities—a process called doping—or under the influence of electrical fields or light.

In the context of the exercise, the element with semiconductor properties would have moderate ionization energy—not as low as a typical metal but not as high as a non-metal. This property underpins the utility of semiconductors in electronic devices like transistors and diodes, where control over electrical current is necessary. Hence, semiconductors bridge the gap in understanding the transition from metallic to non-metallic character within the periodic elements.

Electrical Conductivity

Electrical conductivity is a measure of how well a material can conduct an electric current. Elements that are good conductors have free and delocalized electrons that allow them to conduct electricity with ease. This is typical for metals which exhibit high electrical conductivity. On the other hand, insulators have tightly bound electrons that prevent electrical flow, while semiconductors lie in between these extremes.

The key to understanding electrical conductivity lies in electron mobility. The conductivity increases with the ease with which electrons can move through a material. This ties back to the exercise, where element Y is described to have a lower ionization energy and is, therefore, likely to be the better conductor, reflecting a greater metallic character compared to element X. Knowing this property and its implications helps students grasp the concept of why some elements are more technologically valuable than others in electronic applications.