Question

According to the general trend, metallic character for a period of elements (increases/decreases) proceeding from left to right in the periodic table.

Short answer

Metallic character decreases from left to right across a period.

Step-by-step solution

Understanding Metallic Character

Metallic character refers to the ability of an element to lose electrons and form positive ions (cations). Elements with high metallic character are usually good conductors of electricity and heat, malleable, and have low ionization energies.

Exploring the Periodic Table Trend

The periodic table is organized in such a way that elements are arranged in periods (rows) and groups (columns). As you move across a period from left to right, the elements become less metallic.

Analyzing Electron Configuration

As you move from left to right across a period, the number of protons increases, leading to a greater nuclear charge. This causes the electrons to be held more tightly, making it more difficult for the element to lose electrons and thereby decreasing its metallic character.

Key concepts

Periodic Table Trends

Understanding the periodic table trends is essential for grasping how elements change in behavior across periods and groups. The periodic table is cleverly arranged in a manner that helps to predict the properties of elements. Rows are called periods, and columns are known as groups.
As you travel across a period from left to right, various characteristics of the elements change systematically, influencing properties like metallic character.
Typically, elements on the left side of a period are metals with high metallic character, meaning they can lose electrons easily and form positive ions. Conversely, moving towards the right results in non-metals with low metallic character due to increased nuclear charge acting on their valence electrons, making them tightly held.

• Metallic Nature: Decreases across a period (left to right).
• Non-Metallic Nature: Increases across a period.

Grasping these trends aids in understanding chemical reactivity and bonding characteristics of elements based on their position in the periodic table.

Ionization Energy

Ionization energy is a key concept when discussing metallic character. It refers to the energy required to remove an electron from an atom in the gas phase. This energy is a reflection of how strongly an atom holds onto its electrons.
When you move from left to right across a period, ionization energy generally increases. This occurs because additional protons in the nucleus exert greater attraction on the electrons, making it more difficult to remove them.
Elements with high ionization energies tend to have low metallic character, as they do not lose electrons easily.

• Trend Across Period: Increases from left to right.
• Reason for Increase: Greater nuclear charge.

Understanding ionization energy helps reveal why certain elements are reactive metals, while others are inert gases. This is crucial for predicting chemical behavior.

Electron Configuration

Electron configuration refers to the arrangement of electrons around an atom's nucleus. This configuration dictates how atoms interact and bond with each other.
The electron configuration significantly impacts an element's metallic character. As we move across a period, the electron configuration becomes more complete, with electrons filling up orbitals progressively. The increased number of electrons corresponds to a higher nuclear charge that holds electrons tighter, thus reducing metallic character.

• Influence on Reactivity: Incomplete configurations (e.g., in metals) make electron loss easier, while complete configurations (e.g., in non-metals) make electron loss harder.
• Electron Configuration & Stability: Elements aim to achieve a stable configuration, often seen in noble gases.

Understanding these aspects of electron configuration can explain why metals typically occur on the left side of the periodic table, where the loss of electrons is more energetically favorable.