Periodic Trends In Properties Of Elements
Chapter Name : Classification Of Elements And Periodicity In Properties |
Sub Topic Code : 102_11_03_07_02 |
Topic Name : Periodic Trends In Properties Of Elements |
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Sub Topic Name : Ionic Radius |
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Introduction
• Atoms that have gained or lost electrons are called ions. • Metals generally give electrons; Nonmetals gain electrons from other atoms. • The ionic radius can be measured by measuring the distances between cations and anions in ionic crystals. • Atoms and ions which contain the same number of electrons are called isoelectronic species. • In general, the ionic radii of elements exhibit the same trend as the atomic radii. • Ionic radius increases from left to right in a period and down a group in the periodic table.
Pre-Requisites:
Element, periodic properties, classification, valence shell, Metals, non-metals
Activity:
Opposites attract and like repels like.
Real Life Question:
How do opposites attract and like repels like?
Key Words / FlashCards
| Key Words | Definitions (pref. in our own words) |
|---|---|
| Ionic Radius | The distance from the center of the nucleus to the “edge” of the electron cloud at the outermost shell of an ion. |
Learning aids / Gadgets
| Gadgets | How it can be used |
|---|---|
| Tennis ball | Measure the approximate radius of a tennis ball. |
Real life uses :
Ionic radius helps to figure out the size of a molecule.
Places to visit :
school
Practical examples around us
| Examples | Explainations |
|---|---|
| Magnet | N side of a magnet attracts the S side. |
What you learn in Theory:
• Atoms that have gained or lost electrons are called ions. • Metals generally give electrons; Nonmetals gain electrons from other atoms. • The ionic radius can be measured by measuring the distances between cations and anions in ionic crystals. • Atoms and ions which contain the same number of electrons are called isoelectronic species. • In general, the ionic radii of elements exhibit the same trend as the atomic radii. • Ionic radius increases from left to right in a period and down a group in the periodic table.
What you learn in Practice:
Larger cations have smaller charges and larger anions and small negative charger.