Making In Order
Chapter Name : Periodic Classification Of Elements |
Sub Topic Code : 102_10_05_02_03 |
Topic Name : Making In Order |
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Sub Topic Name : Limitations Of Mendeleev's Periodic Table |
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Introduction
These three limitations were found in Mendeleev’s table:
· No fixed position of Hydrogen.
· Isotopes defied the Periodic Law.
· Elements yet to be discovered could not be predicted in all cases.
Pre-Requisites:
Periodic table
Activity:
Different make up different substances e.g. water is made of hydrogen and oxygen.
Real Life Question:
How were different elements identified?
Key Words / FlashCards
| Key Words | Definitions (pref. in our own words) |
|---|---|
| Elements | A chemical element is a pure chemical substance consisting of one type of atom distinguished by its atomic number, which is the number of protons in its nucleus. Elements are divided into metals, metalloids, and non-metals. |
Learning aids / Gadgets
| Gadgets | How it can be used |
|---|---|
| A racing track | Center of the track is the nucleus having protons and neutrons, the running tracks are the orbits and the racers are the electrons. |
Real life uses :
For the identification and grouping and classification of elements.
Places to visit :
Laboratory.
Practical examples around us
| Examples | Explainations |
|---|---|
| Water | Water is made of hydrogen and oxygen. |
What you learn in Theory:
These three limitations were found in Mendeleev’s table:
1. No fixed position of Hydrogen.
2. Isotopes defied the Periodic Law.
3. Elements yet to be discovered could not be predicted in all cases.
What you learn in Practice:
For classification of elements.