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प्रश्न
Name and state the following with reference to the elements of the first three periods of the periodic table.
Alkaline earth metal in period 3.
उत्तर
Magnesium
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संबंधित प्रश्न
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 their following characteristics in tabular form:-
(a) The number of electrons in their atoms
(b) The sizes of their atoms
(c) Their metallic character
(d) Their tendencies to lose electrons
(e) The formula of their oxides
(f) The formula of their chlorides
The electrons in the atoms of four elements A, B, C and D are distributed in three shells having 1, 3, 5 and 7 electrons in the outermost shell respectively. State the period in which these elements can be placed in the modern periodic table. Write the electronic configuration of the atoms of A and D and the molecular formula of the compound formed when A and D combine.
The atomic radii of three elements X, Y and Z of a period of the periodic table are 186 pm; 104 pm and 143 pm respectively. Giving a reason, arrange these elements in the increasing order of atomic numbers in the period.
How does the atomic size vary on going down from top to bottom in a group of the periodic table? Why does it vary this way?
Given alongside is a part of the periodic table. As we move vertically downward from Li to fr?
| Li | Be |
| Na | |
| K | |
| Rb | |
| Cs | |
| Fr | |
| rA | Ra |
What happens to the size of atoms?
How do the following change on moving from left to right in a period of the periodic table?
Give examples in support of your answer.
Chemical reactivity of elements ?
An element belongs to the third period and Group IIIA (13) of the periodic table. State: the name of the element.
(a) Fill in the blanks and rewrite the completed statements:
(i) ________ group in the periodic table contains elements that are all gases at room temperature.
(ii) Very fine particles mainly scatter ______ light.
What is the common feature of the electronic configuration of the elements at the end of Period 2 and Period 3?
Select the correct answer from the options given below.
Is the group number of the element whose atomic number is 4.
