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प्रश्न
Write the atomic numbers of two elements 'X' and 'Y' having electronic configuration 2, 8, 2 and 2, 8, 6 respectively.
उत्तर
Atomic number of X = 2 + 8 + 2 = 12
Atomic number of Y = 2 + 8 + 6 = 16
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संबंधित प्रश्न
Study the following table in which positions of six elements A, B, C, D, E and F are shown as they are in the modern periodic table:
|
Group→
Period↓ |
1
|
2
|
3-12
|
13
|
14
|
15
|
16
|
17
|
18
|
| 2 | A | B | C | ||||||
| 3 | D | E | F |
On the basis of the above table, answer the following questions:-
(i) Name the element which forms only covalent compounds.
(ii) Name the element which is a metal with valency three.
(iii) Name the element which is a non-metal with valency three.
(iv) Out of D and E, which is bigger in size and why?
(v) Write the common name for the family to which the elements C and F belong.
Which element has a total of three shells, with four electrons in its valence shell?
An element with the atomic number 19 will most likely combine chemically with the element whose atomic number is ______.
How does the valency of elements change of moving from left to right in the third period of the periodic table?
An element X belongs to group 2 and another element Y belongs to group 15 of the periodic table:
(a) What is the number of valence electron in X?
(b) What is the valency of X?
(c) What is the number of valence electrons in Y?
(d) What is the valency of Y?
Explain how you have arrived at your answers.
How does Nature of oxides of elements change on going from left to right in a period of the periodic table?
Give examples in support of your answer.
The elements A, B, C, D and E have atomic numbers 9, 11, 17, 12 and 13 respectively. The pair of elements which belongs to the same group of the periodic table is:
(a) A and B
(b) B and D
(c) A and C
(d) D and E
An element 'M' has atomic number 12.
(a) Write its electronic configuration.
(b) State the group to which 'M' belongs.
(c) Is 'M' a metal or a non-metal.
(d) Write the formula of its chloride.
Fill in the blank
Oxidising property ________from fluroine to iodine because the power to accpet electron decreases.
The electronic configuration of an element is 2, 8, 4. State it:
group and period in the Modern Periodic Table.
