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प्रश्न
Write a 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, the 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
The element eka-silicon in Mendeleev’s periodic table is known as ………… in the modern periodic table.
Besides gallium, which other elements have since been discovered that were left by Mendeleev in his Periodic Table? (any two)
Why do you think the noble gases are placed in a separate group?
How could the Modern Periodic Table remove various anomalies of Mendeleev’s Periodic Table?
Which of the following statements is not a correct statement about the trends when going from left to right across the periods of periodic Table.
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?
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?
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
An element X forms an oxide X2O3. In which group of Mendeleev's periodic table is this element placed?
(a) group II
(b) group III
(c) group V
(d) group VIII
Why could no fixed position be given to hydrogen in Mendeleev's periodic table?
State the merits of Mendeleev's classification of elements.
The elements from the zero group are called ______.
Find the correlation:
Eka boron : Scandium : : Eka Aluminum : ______
Find the correlation:
Two elements in the same position : demerit of Newland's octaves : : place for Isotopes : ______
Find the odd one out and give its explanation.
Match the columns.
| Column A | Column B |
| 1) Triads | a) Mendeleev |
| 2) Octave | b) Dobereiner |
| 3) Atomic number | c) Thomson |
| 4) Atomic mass number | d) Moseley |
| e) Newland |
Write the name.
The family of group 1 elements.
Write the name.
The family of elements having zero valency.
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 |
