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प्रश्न
Mendeléev predicted the existence of certain elements not known at that time and named two of them as Eka-silicon and Eka-aluminium.
- Name the elements which have taken the place of these elements
- Mention the group and the period of these elements in the Modern Periodic Table.
- Classify these elements as metals, non-metals or metalloids
- How many valence electrons are present in each one of them?
उत्तर
- Eka-Silicon was replaced by germanium, Eka-aluminium was replaced by gallium in the Mendeleev's periodic table.
- Germanium-group number 14 and 4th period.
Gallium-group number 13 and 4th period. - Germanium is a metalloid and gallium is a metal.
- Germanium has 4 electrons and gallium has 3 valence electrons.
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संबंधित प्रश्न
Lithium, sodium, potassium are all metals that react with water to liberate hydrogen gas. Is there any similarity in the atoms of these elements?
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According to Mendeleev's periodic law, the properties of elements are a periodic function of their atomic numbers.
Write the merits of Mendeleev’s periodic table.
Mendeleev's contributions to the concept of a periodic table laid the foundation for the Modern Periodic Table. Give reasons.
Which group of elements was missing from Mendeleev's original periodic table?
Name two elements whose atomic weights were corrected on the basis of their positions in Mendeleev's periodic table.
According to Mendeleev’s periodic law, properties of elements are periodic function of their _______.
In Mendeleev’s Periodic Table, gaps were left for the elements to be discovered later. Which of the following elements found a place in the Periodic Table later?
At the time of Mendeleev, the number of elements known was ______
List the features of Mendeleev’s Periodic Table.
