The Actinides
Chapter Name : The D- And F- Block Elements |
Sub Topic Code : 102_12_08_06_02 |
Topic Name : The Actinides |
|
Sub Topic Name : Ionic Sizes |
|
Introduction
• The actinoids include the fourteen elements
from Th to Lr.
• The general trend in lanthanoids is observable
in the actinoids as well. There is a gradual decrease in the size of atoms or M3+
ions across the series.
•
This may be referred to as the actinoid contraction
(like lanthanoid contraction).
The contraction is,
however, greater from element to element in this series resulting from poor
shielding by 5f electrons
Pre-Requisites:
Periodic table, elements
Activity:
Smoke detectors contain Americium-241, an
actinide.
Real Life Question:
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Key Words / FlashCards
| Key Words | Definitions (pref. in our own words) |
|---|---|
| Group | Group is the vertical column on the periodic table which contains elements having the similar properties |
Learning aids / Gadgets
| Gadgets | How it can be used |
|---|---|
| Smoke detectors | Open up a smoke detector and check out the radioactive label since it contains Americium-241 |
Real life uses :
Smoke detectors contain Americium-241
Places to visit :
kitchen
Practical examples around us
| Examples | Explainations |
|---|---|
| Smoke Detectors | Smoke detectors contain Americium-241 |
What you learn in Theory:
• The actinoids include the fourteen elements
from Th to Lr.
• The general trend in lanthanoids is observable
in the actinoids as well. There is a gradual decrease in the size of atoms or M3+
ions across the series.
•
This may be referred to as the actinoid contraction
(like lanthanoid contraction).
The contraction is,
however, greater from element to element in this series resulting from poor
shielding by 5f electrons
What you learn in Practice:
• The actinoids include the fourteen elements
from Th to Lr.
• The general trend in lanthanoids is observable
in the actinoids as well. There is a gradual decrease in the size of atoms or M3+
ions across the series.
•
This may be referred to as the actinoid contraction
(like lanthanoid contraction).
The contraction is,
however, greater from element to element in this series resulting from poor
shielding by 5f electrons