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प्रश्न
Name or state following with reference to the element of the first three periods of the periodic table.
The formula of the hydroxide of the element having electronic configuration 2, 8, 2.
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उत्तर
Hydroxide of element [2, 8, 2] is Mg [OH], where Mg is the element.
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संबंधित प्रश्न
Rewrite the following statement after correction, if necessary:
Elements in the same period have equal valency
Fill in the blank in the following statement:
In going across a period (right to left) in periodic table, the atomic size of the atom ...............
Fill in the blank in the following statement:
On going down in a group in the periodic table, the metallic character of elements ...............
Atomic number of metal ‚A‛ is 11, while atomic number of metal ‚B‛ is 20. Which of them will be more reactive? Write the chemical reaction of dilute HCl with metal ‚A‛.
Taking into consideration the period of the elements given below, answer the following questions:
| Elements | Atomic Radius (pm) |
| O | 66 |
| B | 88 |
| C | 77 |
| N | 74 |
| Be | 111 |
| Li | 152 |
- Arrange the above elements in decreasing order of their atomic radii.
- State the period to which the above elements belong.
- Why this arrangement of elements is similar to the above period of modern periodic table?
- Which of the above elements have the biggest and the smallest atom?
- What is the periodic trend observed in the variation of atomic radius while going from left to right within a period?
The following questions refer to the Periodic Table.
What is the common feature of the electronic configurations of the elements in group 7?
Arrange the following as per instruction given in the bracket.
K, Pb, Ca, Zn (increasing reactivity)
(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.
The electronic configuration of an element is 2, 8, 4. State it:
name and write its one physical property.
The position of certain elements in the Modern Periodic Table is shown below:
| Group → Period ↓ |
1 | 2 | 3 to 12 | 13 | 14 | 15 | 16 | 17 | 18 |
| 1 | G | H | |||||||
| 2 | A | I | B | C | |||||
| 3 | D | E | F |
Using the above table answer the following questions giving reasons in each case:
- Which element will form only covalent compounds?
- Which element is a non-metal with valency 2?
- Which element is a metal with valency 2?
- Out of H, C, and F which has the largest atomic size?
- To which family does H, C, and F belong?
