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प्रश्न
Write scientific reason.
In a group, the size of the atom increases as it goes down from the top.
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उत्तर
- While going down from the top to bottom in a group, a number of shells increases.
- The outermost electrons go farther and farther from the nucleus, extending the radius and ultimately increasing the size of the atom even though the nuclear charge increases.
Hence, in a group, the size of the atom increases as it goes down from the top.
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संबंधित प्रश्न
Besides gallium, which other elements have since been discovered that were left by Mendeleev in his Periodic Table? (any two)
What were the criteria used by Mendeleev in creating his Periodic Table?
Why do you think the noble gases are placed in a separate group?
What property do all elements in the same column of the Periodic Table as boron have in common?
What property do all elements in the same column of the Periodic Table as fluorine have in common?
An atom has electronic configurations 2, 8, 7.
What is the atomic number of this element?
What was the Mendeleev's basis for the classification of elements?
In the classification of the them known elements, Mendeleev was guided by two factors. What are those two factors?
Name two elements whose properties were predicted on the basis fo their positions in Mendeleev's periodic table.
The three elements predicted by Mendeleev from the gaps in his periodic table were known as eka-boron, eka-aluminimum and eka-silicon. What names were given to these elements when they were discovered later on?
Which group of elements could be placed in Mendeleev's periodic table later on, without disturbing the order? Give reason.
State the periodic law on which Mendeleev's periodic table table was based. Why and how was this periodic law changed?
State the merits of Mendeleev's classification of elements.
Describe two anomalies of Mendeleev's periodic classification of elements.
What name were given by Mendeleev to the then undiscovered element scandium.
What name were given by Mendeleev to the then undiscovered element gallium?
What name were given by Mendeleev to the then undiscovered element germanium?
How do the properties of eka-aluminium element predicted by Mendeleev compare with the actual properties of gallium element?
Why did Mendeleev leave some gaps in his periodic table?
In Mendeleev's periodic table, why was there no mention of noble gases like helium, neon and argon?
State any three limitations of Mnedeleev's classification of elements.
Besides gallium, which two other elements have since been discovered for which Mendeleev had left gaps in his periodic table?
Which group of elements was missing from Mendeleev's original periodic table?
In Mendeleev's periodic table, gap was not left for one of the following elements. This element is:
(a) gallium
(b) beryllium
(c) germanium
(d) scandium
According to Mendeleev's periodic law, the elements were arranged in the periodic table in the order of: ______
In Mendeleev's periodic table, gaps were left for the elements to be discovered later on. An element which found a vacant place in the periodic table later on is:
(a) Be
(b) Si
(c) Ge
(d) Se
The correct formula of the oxide of Eka-aluminium element predicted by Mendeleev was:
(a) EaO3
(b) Ea3O2
(c) Ea2O3
(d) EaO
State the merits of Mendeleev's classification of elements.
The elements from the zero group are called _______.
Eka boron : Scandium : : Eka Aluminum : _______
Two elements in the same position : demerit of Newland's octaves : : place for Isotopes : _______
Find the odd one out and give its explanation.
Find the odd one out and give its explanation.
Match the columns.
| Column A | Column B |
| 1) Eka-aluminium | a) Scandium |
| 2) Eka-Silicon | b) Gallium |
| 3) Eka- boron | c) Germanium |
| d) Beryllium |
Write the name.
The family of group 1 elements.
Write the name.
The family of elements having zero valency.
Describe the merits of Mendeleev’s periodic table?
An atom has electronic configurations 2, 8, 7.
To which of the following elements would it be chemically similar? (Atomic numbers are given in parentheses.)
Which one of the following does not increase while moving down the group of the periodic table?
Match the column:
| Column ‘A’ | Column ‘B’ |
| Alkali metals | (a) Group 18 |
| Halogens | (b) Group 1 |
| Noble gases | (c) Group 17 |
