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प्रश्न
Name the scientist who stated the modern periodic law.
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उत्तर
Henry Moseley stated the modern periodic law.
संबंधित प्रश्न
How were the positions of isotopes of an element decided in the modern periodic table?
Which of the following statement is correct in regard to the classification of elements?
(a) Elements in modern periodic table are arranged on the basis of increasing atomic masses.
(b) Elements in Mendeleev's periodic table are arranged on the basis of increasing atomic numbers.
(c) In modern periodic table, the element nickel of lower atomic mass is kept before the element cobalt of higher atomic mass.
(d) In modern periodic table, the isotopes of chlorine having different atomic masses are kept in the same group.
What is the number of valence electrons in the atoms of first elements in a period?
Explain why All the elements of a group have similar chemical properties.
What happens to the number of valence electrons in the atoms of elements as we go down in a group of the periodic table?
Two elements P and Q belong to the same period of the modern periodic table and are in group 1 and group 2, respectively. Compare the following characteristics in the tabular form.
- Number of electrons in their atoms
- Their tendency to lose electrons
- Their metallic characters
- Formation of their oxides
- Formulae of their chlorides
p-block is composed of groups 1 and 2.
On moving from left to right in a period in the periodic table, the size of the atom ______
Spot the error:
There are 5 periods and 17 groups in the modern periodic table.
Select the appropriate options and complete the following paragraph:
(metals, non-metals, metalloids, four, seven, s-block, p-block, d-block, f-block).
On the basis of electronic configuration, elements in the modern periodic table are classified Into ______ blocks. Groups 1 and 2 elements are included in ______ and all these elements are metals. (except Hydrogen). Group 13 to 18 elements are included in ______. This block contains metals, non-metals and metalloids. Group 3 to 12 elements are included in ______ and all the elements are ______ elements shown at the bottom of the periodic table i.e. Lanthanides and Actinides constitute ______ and all these elements are metals.
