Group-1 Elements: The Alkali Metals
Chapter Name : The S- Block Elements |
Sub Topic Code : 102_11_10_02_02 |
Topic Name : Group-1 Elements: The Alkali Metals |
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Sub Topic Name : Atomic And Ionic Radii |
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Introduction
• Group 1 of the Periodic Table consists of the elements: lithium, sodium, potassium, rubidium, cesium and francium. • They are collectively known as the alkali metals. • These are so called because they form hydroxides on reaction with water which are strongly alkaline in nature. • The alkali metal atoms have the largest sizes in a particular period of the periodic table. • With increase in atomic number, the atom becomes larger. • The monovalent ions (M+) are smaller than the parent atom. • The atomic and ionic radii of alkali metals increase on moving down the group i.e., they increase in size while going from Li to Cs.
Pre-Requisites:
Alkali metals, periodic table, s-block
Activity:
Nerve impulse conduction, Sodium is a primary ingredient of common salt.
Real Life Question:
How do nerve impulses work?
Key Words / FlashCards
| Key Words | Definitions (pref. in our own words) |
|---|---|
| Alkali metals | • Group 1 elements. |
Learning aids / Gadgets
| Gadgets | How it can be used |
|---|---|
| needle | Prick your finger with a needle lightly. See how the nerve impulse travels through and reaches the brain detecting pain. Sodium calcium and Potassium ions play a major role in nerve impulse conduction. |
Real life uses :
Nerve impulse conduction.
Places to visit :
Kitchen.
Practical examples around us
| Examples | Explainations |
|---|---|
| salt | Salt contains sodium. |
What you learn in Theory:
• The alkali metal atoms have the largest sizes in a particular period of the periodic table. • With increase in atomic number, the atom becomes larger. • The monovalent ions (M+) are smaller than the parent atom. • The atomic and ionic radii of alkali metals increase on moving down the group i.e., they increase in size while going from Li to Cs.
What you learn in Practice:
• Alkali metals form hydroxides on reaction with water which are strongly alkaline in nature.