General Properties Of The Transition Elements
Chapter Name : The D- And F- Block Elements |
Sub Topic Code : 102_12_08_03_02 |
Topic Name : General Properties Of The Transition Elements |
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Sub Topic Name : Variation In Atomic And Ionic Sizes Of Transition Metals |
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Introduction
•
In general, ions of the same charge in a given series
show progressive decrease in radius with the increasing atomic number.
•
This is trend is seen as a new electron enters a d
orbital each time the nuclear charge increases by 1.
•
Also, the shielding effect of a d electron is not that
effective, and so the net electrostatic attraction between the nuclear charge
and the outermost electron increases and the ionic radius decreases.
•
Variation within a series is quite small.
When atomic sizes of
one series are compared with those of the corresponding elements in the other
series, we can see that there is an increase in radii from the first (3d) to
the second (4d) series but the radii of the third (5d) series is almost the
same as those of the corresponding (4d) members.
Pre-Requisites:
Periodic table, elements, atomic size
Activity:
Various precious metals such as silver, gold and
platinum and industrially important
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 |
|---|---|
| Gold coin Iron Rod | Gold, Iron, copper are members of the transition metals. Compare their properties |
Real life uses :
To make jewellery, utensils
Places to visit :
Bank, jewellery shop
Practical examples around us
| Examples | Explainations |
|---|---|
| Gold coins | • Various precious metals such as silver, gold and platinum and industrially important |
What you learn in Theory:
•
In general, ions of the same charge in a given series
show progressive decrease in radius with the increasing atomic number.
•
This is trend is seen as a new electron enters a d
orbital each time the nuclear charge increases by 1.
•
Also, the shielding effect of a d electron is not that
effective, and so the net electrostatic attraction between the nuclear charge
and the outermost electron increases and the ionic radius decreases.
•
Variation within a series is quite small.
When atomic sizes of
one series are compared with those of the corresponding elements in the other
series, we can see that there is an increase in radii from the first (3d) to
the second (4d) series but the radii of the third (5d) series is almost the
same as those of the corresponding (4d) members.
What you learn in Practice:
•
In general, ions of the same charge in a given series
show progressive decrease in radius with the increasing atomic number.
•
This is trend is seen as a new electron enters a d
orbital each time the nuclear charge increases by 1.
•
Also, the shielding effect of a d electron is not that
effective, and so the net electrostatic attraction between the nuclear charge
and the outermost electron increases and the ionic radius decreases.
•
Variation within a series is quite small.
When atomic sizes of
one series are compared with those of the corresponding elements in the other
series, we can see that there is an increase in radii from the first (3d) to
the second (4d) series but the radii of the third (5d) series is almost the
same as those of the corresponding (4d) members.