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प्रश्न
Why was Dobereiner's triad discarded?
उत्तर
Döbereiner failed to arrange all the known elements in the form of triads.
In the triad of fluorine (19), chlorine (35.5) and bromine (80), it is observed that the mean of the atomic masses of fluorine and bromine is ½(19 + 80) = 49.5, not 35.5.
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संबंधित प्रश्न
The modern periodic table has been evolved through the early attempts of Dobereiner, Newland and Mendeleev. List one advantage and one limitation or all the three attempts.
Name the scientist who gave Law of triads in the early classification of elements.
A, B and C are the elements of a Dobereiner's triad. If the atomic mass of A is 7 and the of C is 39, what should be the atomic mass of B?
What were the limitations of Dobereiner's classification of elements?
The atomic masses of three elements X, Y and Z having similar chemical properties are 7, 23 and 39 respectively.
(a) Calculate the average atomic mass of elements X and Z.
(b) How does the average atomic mass of elements X and Z compare with the atomic mass of element Y?
(c) Which law of classification of elements is illustrated by this example?
(d) What could the elements X, Y and Z be?
(e) Give another example of a set of elements which can be classified according to this law.
Can the following groups of elements be classified as Dobereiner's triad:
Na, Si, Cl
Atomic mass of Na - 23, Si - 28, Cl - 35.
Justify your answer.
Find the odd one out and give its explanation.
Find the odd one out and give its explanation.
State Dobereiner’s Law of Triads.
Can the following groups of elements be classified as Döbereiner's triad?
- Na, Si, Cl
- Be, Mg, Ca
Atomic mass of Be 9; Na 23; Mg 24; Si 28; Cl 35; Ca 40 Explain by giving reason.
