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प्रश्न
Did Dobereiners triads also exist in the columns of Newland's Octaves? Compare and find out.
उत्तर
Yes, Döbereiner's triads also exist in the columns of Newland's octaves. For example, the second column of Newlands classification has the elements Lithium (Li), Sodium (Na) and Potassium (K), which constitute a Döbereiner's triad.
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संबंधित प्रश्न
Did Dobereiner’s triads also exist in the columns of Newlands’ Octaves? Compare and find out.
The arrangement of elements in a group of three is known as ________.
State one example of a Dobereiner's triad, showing in it that the atomic mass of middle element is half-way between those of the other two.
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.
A, B and C are the elements of a Dobereiner's triad. If the atomic mass of A is 7 and that of C is 39, what should be the atomic mass of B?
Why was Dobereiner's triad discarded?
Dobereiner laid down the _______ rule.
According to Dobereiner’s triads rule, three elements in an increasing order of atomic mass shows _______.
Match the following.
| 1. | Triads | Newlands |
| 2. | Alkali metal | Calcium |
| 3. | Law of octaves | Henry Moseley |
| 4. | Alkaline earth metal | Sodium |
| 5. | Modern Periodic Law | Dobereiner |
Pick out the chemically most reactive elements from the given triads.
Li, Na, K F, Cl, Br
