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State Dobereiner's law of triads.

Important Questions on Periodic classification of elements

EASY
Chemistry>Chemistry - Xth Grade>Periodic classification of elements>Early Attempts at the Classification of Elements
Who proposed the law of Octaves? 
MEDIUM
Chemistry>Chemistry - Xth Grade>Periodic classification of elements>Early Attempts at the Classification of Elements
Write the name of the scientist who has given the octave rule for the classification of elements. Explain the octave rule.
MEDIUM
Chemistry>Chemistry - Xth Grade>Periodic classification of elements>Early Attempts at the Classification of Elements
Write the name of the scientist who has given a triad law for the classification of elements. Explain the law of triad.
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Chemistry>Chemistry - Xth Grade>Periodic classification of elements>Early Attempts at the Classification of Elements
State the limitations of Newlands' Law of Octaves?
MEDIUM
Chemistry>Chemistry - Xth Grade>Periodic classification of elements>Early Attempts at the Classification of Elements
The modern periodic table has been evolved through the early attempts of Dobereiner, Newland and Mendeleev. List one advantage and one limitation of all the three attempts.
EASY
Chemistry>Chemistry - Xth Grade>Periodic classification of elements>Early Attempts at the Classification of Elements
Write Newlands Law of 'Octaves' for classification of elements.
MEDIUM
Chemistry>Chemistry - Xth Grade>Periodic classification of elements>Early Attempts at the Classification of Elements
Classification of elements helps us to
HARD
Chemistry>Chemistry - Xth Grade>Periodic classification of elements>Early Attempts at the Classification of Elements
What is Newlands’ Law of Octaves? What were the limitations of Newlands’ Law of Octaves? 
 
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Chemistry>Chemistry - Xth Grade>Periodic classification of elements>Early Attempts at the Classification of Elements

Chlorine, Bromine, and Iodine form a Dobereiner's Triad. If the approximate atomic mass of Chlorine is 35 and that of Iodine is 127:

Find the atomic mass of Bromine.

HARD
Chemistry>Chemistry - Xth Grade>Periodic classification of elements>Early Attempts at the Classification of Elements
Can the following groups of elements be classified as Dobereiner’s triad?

(a) Na, Si, CI
(b) Be, Mg, Ca
Atomic mass of Be 9; Na 23; Mg 24; Si 28; Cl 35; Ca 40

Explain by giving a reason.
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Chemistry>Chemistry - Xth Grade>Periodic classification of elements>Early Attempts at the Classification of Elements
Calcium, Strontium and Barium form a Dobereiner’s triad. The atomic masses of calcium and barium are 44 and 137 respectively. Predict the atomic mass of strontium.
HARD
Chemistry>Chemistry - Xth Grade>Periodic classification of elements>Early Attempts at the Classification of Elements
(i) State the law of octaves,
(ii) Name the scientist who framed the above law.
(iii) Two elements A and B obey the law of octaves. How many elements are in between A and B?
HARD
Chemistry>Chemistry - Xth Grade>Periodic classification of elements>Early Attempts at the Classification of Elements
Cl, Li, Ca, Br, Na,Sr, I, K and Ba. From the list of elements given above make three triads and name the family of each triad,
EASY
Chemistry>Chemistry - Xth Grade>Periodic classification of elements>Early Attempts at the Classification of Elements
Why was the system of classification of elements into triads not found suitable?
HARD
Chemistry>Chemistry - Xth Grade>Periodic classification of elements>Early Attempts at the Classification of Elements
The three elements A. B and C with similar properties have atomic masses X. Y and Z respectively. The mass of Y is approximately equal to the average mass of X and Z. What is such an arrangement of elements called?
Give one example of such a set of elements.
MEDIUM
Chemistry>Chemistry - Xth Grade>Periodic classification of elements>Early Attempts at the Classification of Elements
What were the limitations of Newlands’ Law of Octaves?
HARD
Chemistry>Chemistry - Xth Grade>Periodic classification of elements>Early Attempts at the Classification of Elements
(j) What is the achievement of Dobereiner’s law of triads?

(ii) What were the reasons for rejecting this classification?
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Chemistry>Chemistry - Xth Grade>Periodic classification of elements>Early Attempts at the Classification of Elements
What were the limitations of Dobereiner’s classification?
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Chemistry>Chemistry - Xth Grade>Periodic classification of elements>Early Attempts at the Classification of Elements
The three imaginary elements X, Y and Z  represent a Dobereiner's triad. If the atomic mass of the element X is 14 and that of element Y is 46, then the atomic mass of element Z will be:
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Chemistry>Chemistry - Xth Grade>Periodic classification of elements>Early Attempts at the Classification of Elements
Why is there a necessity for the classification of elements? Give at least two reasons.