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Periodic Classification of Elements
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Compare and contrast the arrangement of elements in Mendeléev’s Periodic Table and the Modern Periodic Table.
Option A
Option B
Option C
Option D
Solution
| Mendeleev's periodic table | Modern periodic table | ||
| $1.$ | Elements are arranged in the increasing order of their atomic masses. | $1.$ | Elements are arranged in the increasing order of their atomic numbers. |
| $2.$ | There are a total of $7$ groups (columns) and $6$ periods (rows). | $2.$ | There are a total of $18$ groups (columns) and $7$ periods (rows). |
| $3.$ | Elements having similar properties were placed directly under one another. |
$3.$ | Elements having the same valence shell are present in the same period while elements having the same number of valence electrons are present in the same group. |
| $4.$ | The position of hydrogen could not be explained. | $4.$ | Hydrogen is placed above alkali metals. |
| $5.$ | No distinguishing positions for metals and non-metals. | $5.$ | Metals are present at the left hand side of the periodic table whereas non-metals are present at the right hand side. |
Standard 10
Science
Similar Questions
The position of three elements $A$, $B$ and $C$ in the Periodic Table are shown below
| Group $16$ | Group $17$ |
| – | – |
| – | $A$ |
| – | – |
| $B$ | $C$ |
$(a)$ Will $C$ be larger or smaller in size than $B$ ?
$(b) $ Which type of ion, cation or anion, will be formed by element $A$ ?
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The position of three elements $A$, $B$ and $C$ in the Periodic Table are shown below
| Group $16$ | Group $17$ |
| – | – |
| – | $A$ |
| – | – |
| $B$ | $C$ |
$ (a)$ State whether $A$ is a metal or non-metal.
$(b)$ State whether $C$ is more reactive or less reactive than $A$.
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