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प्रश्न
State whether the following statement is true or false
Similar electronic configuration is repeated after intervals of 2, 8, 8, 18 and 32.
पर्याय
True
False
उत्तर
True
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संबंधित प्रश्न
The atomic masses of three elements A, B and C having similar chemical properties are 7, 23 and 39, respectively.
- Calculate the average atomic mass of elements A and C.
- Compare the average atomic mass with atomic mass of B.
- What could the elements A, B and C be?
The position of eight elements in the Modern Periodic Table is given below where atomic numbers of elements are given in the parenthesis.
| Period No. | ||
| 2 | Li(3) | Be(4) |
| 3 | Na(11) | Mg(12) |
| 4 | K(19) | Ca(20) |
| 5 | Rb(37) | Sr(38) |
(i) Write the electronic configuration of Ca.
(ii) Predict the number of valence electrons in Rb.
(iii) What is the number of shells in Sr?
(iv) Predict whether K is a metal or a non – metal.
(v) Which one of these elements has the largest atom in size?
(vi) Arrange Be, Ca, Mg and Rb in the increasing order of the size of their respective atoms.
Fill in the blank in the following statement:
The tendency to gain an electron ............... on moving down in a group of the periodic table.
State the trends in physical properties on moving down the group. Give an example to illustrate.
An element X belong to 3rd periods and group II of the periodic table state:
the valency,
Name the element in period 3 which does not form oxide.
Select the correct answer
Number of shells in potassium are
What is meant by a group in the periodic table?
What is the common feature of the electronic configuration of the elements at the end of Period 2 and Period 3?
Name the period which is the shortest period of the periodic table.
