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The number of elements known when Mendeleev presented periodic table is

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Important Questions on Periodicity

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Mendeleev's periodic law states that the properties of elements are a periodic function of their
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Henry Moseley studied characteristic X-ray spectra of elements. The graph which represents his observation correctly is
Given v= Frequency of X-ray emitted
         Z= Atomic number
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Identify the incorrect match.

Name IUPAC Official Name
(a) Unnilunium (i) Mendelevium
(b) Unniltrium (ii) Lawrencium
(c) Unnilhexium (iii) Seaborgium
(d) Unununium (iv) Darmstadtium
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In which of the following options, the law of triad is applicable?
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Which one of the following statements for D.I. Mendeleev, is incorrect ?
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It is observed that characteristic X-ray spectra of elements show regularity. When frequency to the power 'n' i.e. vn of X-rays emitted is plotted against atomic number Z, the following graph is obtained.

Question Image

The value of 'n' is

 

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The atomic number of the element unnilennium is :
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Which of the given atoms has the greatest electron affinity?
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Which one of the following element is represented as Eka-Silicon in Mendeleev's periodic table?
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Mendeleev's Periodic Table is upset by the fact that
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How many elements were known when Mendeleev presented the periodic table ?
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Which of the following element have maximum atomic volume?
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Lother Meyer obtained the curve for the known elements by plotting their atomic volumes against
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The atomic masses of Li and K are 7 and 39, respectively. According to law of triads the atomic mass of Na will be
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In Lother Meyer plot, the peaks are occupied by