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प्रश्न
State the merits of Mendeleev's classification of elements.
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उत्तर
Merits of Mendeleev's classification of elements:
- Grouping of elements
- Gaps for undiscovered elements: Mendeleev left some gaps in his periodic table for subsequent inclusion of elements not known at that time.
- He predicted the properties of the then-unknown elements on the basis of properties of elements lying adjacent to the vacant slots (eka-aluminum and eka-silicon).
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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)
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?
Why did Mendeleev leave some gaps in his periodic table?
Which group of elements was missing from Mendeleev's original periodic table?
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 elements from the zero group are called _______.
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 |
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?
