Question

Which element would you expect to be more metallic? (a) \(\mathrm{S}\) or \(\mathrm{Cl}\) (b) In or Al (c) As or Br

Short answer

S is more metallic than Cl, In is more metallic than Al, and As is more metallic than Br.

Step-by-step solution

Understanding Metallic Character

Metallic character refers to how easily an element can lose electrons. Elements with higher metallic character are more likely to lose electrons and form positive ions.

Determine Position in Periodic Table

Check the position of each element in the periodic table. Generally, metallic character increases as you move from top to bottom within a group and decreases as you move from left to right across a period.

Comparing S and Cl

Sulfur (S) is in Group 16 and Chlorine (Cl) is in Group 17 of the periodic table. Since Cl is to the right of S in the same period, S is more metallic than Cl because S is better at losing electrons.

Comparing In and Al

Indium (In) is in Group 13 and Period 5, whereas Aluminum (Al) is in Group 13 and Period 3. Since In is below Al in the same group, In is more metallic than Al due to the increased tendency to lose electrons as we move down the group.

Comparing As and Br

Arsenic (As) is in Group 15 and Period 4, whereas Bromine (Br) is in Group 17 and Period 4. Since As is to the left of Br in the same period, As is more metallic than Br because elements on the left are more metallic compared to those on the right.

Key concepts

Periodic Table

The periodic table is a crucial tool in understanding the properties of elements. Each element is arranged based on its atomic number, which is the number of protons in its nucleus. This helps in predicting chemical behavior.
As you move from left to right across a period (a horizontal row), elements become less metallic.
Conversely, as you move from top to bottom down a group (a vertical column), elements become more metallic.
This pattern helps us understand why Indium (In), which is below Aluminum (Al) on the periodic table, is more metallic. Similarly, because Sulfur (S) is to the left of Chlorine (Cl), it is more metallic. Understanding these trends is essential in comparing the metallic character of different elements.

Electron Loss

Metallic character refers to how easily an element can lose electrons. This means elements with higher metallic character can lose electrons effortlessly, which makes them more likely to form positive ions. This tendency of losing electrons is more in metals because their atomic structure allows electrons to be released more freely.
For example, compare Aluminum (Al) and Indium (In). Since In is further down the group, its electrons are less tightly bound to the nucleus compared to Al. This makes In more likely to lose electrons, showing higher metallic character. Similarly, elements on the left side of the periodic table, like Sulfur (S), have a greater tendency to lose electrons compared to elements on the right, like Chlorine (Cl).

Element Comparison

Comparing elements' metallic character involves looking at their positions on the periodic table and their ability to lose electrons.
Let's go through some examples:

• **Sulfur (S) vs. Chlorine (Cl)**: Since S is to the left of Cl in the same period, S is more metallic. This is because elements on the left tend to lose electrons more easily.
• **Indium (In) vs. Aluminum (Al)**: In is below Al in Group 13. As you move down a group, elements have a higher tendency to lose electrons, making In more metallic than Al.
• **Arsenic (As) vs. Bromine (Br)**: As is to the left of Br in the same period. This means As has a higher metallic character being more capable of losing electrons easily compared to Br.

Understanding these comparisons allows you to predict and explain the behavior of elements based on their positions in the periodic table.