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Question
According to Dobereiner’s triads rule, three elements in an increasing order of atomic mass shows _______.
Solution
According to Dobereiner’s triads rule, three elements in an increasing order of atomic mass shows the atomic mass of the middle element in each triad approximately equal to the mean of the atomic masses of the other two elements.
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RELATED QUESTIONS
What were the limitations of Dobereiner’s classification?
The arrangement of elements in a group of three is known as ________.
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.
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.
What is Debereiner's law of triads? Explain with the help of one example of a Dobereiner's triad.
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 triads?
(a) Na, Si, Cl
(b) Be, Mg, Ca
Give reason for your answer.
(Atomic masses : Be 9 ; Na 23 ; Mg 24 ; Si 28 ; Cl 35.5 ; Ca 40)
In Dobereiner’s triad containing Li, Na, K, if atomic masses of Lithium & Potassium are 6.9 and 39.1, then what will be the atomic mass of Sodium?
Why was Dobereiner's triad discarded?
With an example, explain Dobereiner's Triads.
Can the following groups of elements be classified as Dobereiner's triad:
Be, Mg, Ca
Atomic mass of Be - 9, Mg - 24, Ca - 40.
Justify your answer.
What was Dobereiner’s basis, of classification of elements?
State Dobereiner’s Law of Triads with suitable examples.
Explain why Dobereiner’s method of classification of elements did not hold much weightage for future classification.
Dobereiner laid down the _______ rule.
Find the odd one out and give its explanation.
Find the odd one out and give its explanation.
Write the characteristic of Dobereiner’s triads?
Write the name.
The atom having the biggest atomic size from period 2.
In Dobereiner’s triads, the atomic weight of the middle element is ______ the of the atomic masses of 1st and 3rd elements.
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
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.
