Question

Which would you expect to be the more ductile element, (a) \(\mathrm{Ag}\) or \(\mathrm{Mo}\), (b) \(Z n\) or Si? In each case explain your reasoning.

Short answer

In summary, the more ductile elements in each pair are \(Ag\) (silver) and \(Zn\) (zinc). This is because ductility increases from right to left across a period and from top to bottom within a group in the periodic table. Silver is more to the left than molybdenum in the same period, while zinc is both to the left and below silicon, making them more ductile than their counterparts.

Step-by-step solution

Part (a): Comparing Ag and Mo

The first step is to locate Ag (Silver) and Mo (Molybdenum) on the periodic table. Ag is in group 11 and period 5, while Mo is in group 6 and period 5. Both elements are in the same period, so we can compare their groups to determine the more ductile element. In general, ductility increases from right to left across a period and from top to bottom within a group due to the increasing metallic character of the elements. Since Ag is in group 11 and Mo is in group 6, and because Ag is more to the left than Mo, we can infer that Ag will be more ductile than Mo.

Part (b): Comparing Zn and Si

Next, we will locate Zn (Zinc) and Si (Silicon) on the periodic table. Zn is in group 12 and period 4, while Si is in group 14 and period 3. As these elements are neither in the same group nor the same period, we should compare both their group and periodic trends. As previously mentioned, ductility increases from right to left across a period and from top to bottom within a group. Zn is in group 12 and Si is in group 14, so Zn is more to the left than Si, which implies Zn should be more ductile. Moreover, Zn is in period 4 and Si is in period 3, so Zn is below Si, which also suggests that Zn will be more ductile. Therefore, considering both trends, we can conclude that Zn is more ductile than Si. In summary, Ag is more ductile than Mo, and Zn is more ductile than Si. This reasoning is based on the periodic trends of ductility and metallic character.

Key concepts

Periodic Table Trends

The periodic table is a powerful tool that helps us predict the properties of elements, like ductility, based on their position.

One major trend is that:

• Elements become more metallic and generally more ductile as you move from right to left across a period.
• Ductility also increases when moving down a group from top to bottom.

This occurs because moving to the left or down the table increases the metallic characteristics. Metals are typically more ductile due to their atomic structure allowing layers to slide past each other without breaking bonds.

For example, in comparing silver (Ag) and molybdenum (Mo) from our exercise, both being in the same period simplifies the choice. Ag is more metallic (to the left) than Mo, making it more ductile. Similarly, Zinc (Zn) compared to Silicon (Si) falls under this logic, as Zn is leftward and downward in the table, thus inherently more ductile.

Metallic Character

Metallic character is a key concept that influences an element's properties like ductility, conductivity, and luster. It refers to how easily an atom can lose electrons to form positive ions.

The trend of increasing metallic character aligns with the trends in the periodic table. Elements to the left and downwards in the periodic table, such as alkali and alkaline earth metals, exhibit stronger metallic characteristics.

These elements have:

• Lower ionization energy, making them readily lose electrons.
• A malleable and ductile structure that allows easy deformation.
• Good electrical and thermal conductivity.

In the exercise case, Zinc and Silver exhibit higher metallic character than Silicon and Molybdenum, respectively. This accounts for their increased ductility.

Comparative Analysis of Elements

When comparing elements for properties like ductility, it is essential to analyze them based on their periodic table positions. This can be done using specific properties and trends.

A comparative analysis involves:

• Identifying the period and group of each element.
• Evaluating their metallic character and position relative to each other.
• Understanding that elements to the left and lower in the table are typically more ductile.

In our problem, we compare Silver with Molybdenum and Zinc with Silicon. Silver and Zinc, positioned leftward and lower relative to their counterparts, exhibit stronger metallic properties.

Thus, recognizing these trends allows us to easily determine that elements like Ag and Zn are more ductile, leveraging both their periodic and metallic position advantages.