Making In Order- The Modern Periodic Table
Chapter Name : Periodic Classification Of Elements |
Sub Topic Code : 102_10_05_03_03 |
Topic Name : Making In Order- The Modern Periodic Table |
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Sub Topic Name : Trends In The Modern Periodic Table |
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Introduction
·
Valency
increases across a period.
·
Valency
remains same down a group.
·
Atomic
size decreases across a period.
·
Atomic
size increases down a group.
·
Increase
in atomic size down a group happens because the number of shell increases.
·
In
left of periodic table we have metals.
·
At
right of periodic table we have non metals.
·
In
the middle we have semi-metals or metalloids. They exhibit the property
of both, metals and non metals.
·
In
the periodic table a zig zag line separates metals from non metals.
·
Elements
on this zig-zag border are Boron, Silicon, Germanium, Arsenic,
Antimony, Tellurium and Polonium. They all are metalloids/semi-metals.
Pre-Requisites:
Periodic table
Activity:
Study the arrangement of different elements in the
periodic table and see the similarity in properties within the same group or
period.
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 |
|---|---|
| Periodic table | Study the arrangement of different elements in the periodic table. |
Real life uses :
For the identification and grouping and classification
of elements.
Places to visit :
Laboratory.
Practical examples around us
| Examples | Explainations |
|---|---|
| Metals (Iron, Copper, Lead) | All these substances have similar properties. |
What you learn in Theory:
·
Valency
increases across a period.
·
Valency
remains same down a group.
·
Atomic
size decreases across a period.
·
Atomic
size increases down a group.
·
Increase
in atomic size down a group happens because the number of shell increases.
·
In
left of periodic table we have metals.
·
At
right of periodic table we have non metals.
·
In
the middle we have semi-metals or metalloids. They exhibit the property
of both, metals and non metals.
·
In
the periodic table a zig zag line separates metals from non metals.
·
Elements
on this zig-zag border are Boron, Silicon, Germanium, Arsenic,
Antimony, Tellurium and Polonium. They all are
metalloids/semi-metals.
What you learn in Practice:
For classification of elements.