Group-1 Elements: The Alkali Metals
Chapter Name : The S- Block Elements |
Sub Topic Code : 102_11_10_02_06 |
Topic Name : Group-1 Elements: The Alkali Metals |
|
Sub Topic Name : Chemical Properties |
|
Introduction
• The alkali metals are highly reactive due to their large size and low ionization enthalpy. The reactivity of these metals increases down the Group. • The alkali metals tarnish in dry air due to the formation of their oxides which in turn react with moisture to form hydroxides. • They burn vigorously in oxygen forming oxides. • The alkali metals react with water to form hydroxide and dihydrogen. • The alkali metals react with dihydrogen at about 673K (lithium at 1073K) to form hydrides. • The alkali metals readily react vigorously with halogens to form ionic halides. • The alkali metals are strong reducing agents, lithium being the most and sodium the least powerful. • The alkali metals dissolve in liquid ammonia giving deep blue solutions which are conducting in nature.
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 metals are highly reactive due to their large size and low ionization enthalpy. The reactivity of these metals increases down the Group. • The alkali metals tarnish in dry air due to the formation of their oxides which in turn react with moisture to form hydroxides. • They burn vigorously in oxygen forming oxides. • The alkali metals react with water to form hydroxide and dihydrogen. • The alkali metals react with dihydrogen at about 673K (lithium at 1073K) to form hydrides. • The alkali metals readily react vigorously with halogens to form ionic halides. • The alkali metals are strong reducing agents, lithium being the most and sodium the least powerful. • The alkali metals dissolve in liquid ammonia giving deep blue solutions which are conducting in nature.
What you learn in Practice:
• The alkali metals are strong reducing agents, lithium being the most and sodium the least powerful.