Periodic Trends in Properties of Elements

The periodic trends in the properties of elements are crucial for understanding the chemical behavior of elements. Here are some key trends as per the NCERT Class 11 Chemistry:

• Atomic Radius: Decreases across a period from left to right due to increased nuclear charge. Increases down a group due to the addition of shells.
• Ionization Energy: Increases across a period due to higher nuclear charge. Decreases down a group due to increased distance from the nucleus.
• Electronegativity: Increases across a period as atoms strive to complete their valence shell. Decreases down a group as the atomic size increases.
• Electron Affinity: Generally becomes more negative across a period. Less negative down a group.
• Metallic Character: Decreases across a period. Increases down a group.

Understanding these trends is essential for predicting the reactivity and properties of elements.