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प्रश्न
Name the elements in the correct order of their increasing atomic numbers present in the first, second, and third short periods of the periodic table.
State which of the elements are –
- metallic
- non-metallic
- noble gases
in each of the periods 2 and 3.
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उत्तर
Names of elements of:
| Period first | Hydrogen | Helium |
| H | He |
| Period – 2 | Li | Be | B | C | N | O | F | Ne |
| Lithium | Beryllium | Boron | Carbon | Nitrogen | Oxygen | Fluorine | Neon |
| Period – 3 | Na | Mg | Al | Si | P | S | Cl | Ar |
| Sodium | Magnesium | Alummium | Silicon | Phosphorus | Sulphur | Chlorine | Argo |
- Metals: Li, Be, Na, Mg, Al
- Non-metals: C, N, O, F, P, S, Cl
- Noble – gases: Ne, Ar
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संबंधित प्रश्न
How many groups and periods are there in the modern periodic table?
Na, Mg and Al are the elements of the same period of Modern Periodic Table having, one, two and three valence electrons respectively. Which of these elements (i) has the largest atomic radius, (ii) is least reactive? Justify your answer stating reason for each case.
Which element has twice as many electrons in its second shell as in its first shell?
Arrange the following as per instruction given in the bracket.
Cs, Na, Li, K, Rb (increasing metallic character)
Arrange the following as per instruction given in the bracket.
Li, K, Na, H ( decreasing order of their potential ionisation )
Moving left to right in the second period, the number of valence electrons _____.
The electronic configuration of an element is 2, 8, 4. State it:
group and period in the Modern Periodic Table.
What is the common feature of the electronic configuration of the elements at the end of Period 2 and Period 3?
Name or state following with reference to the element of the first three periods of the periodic table.
A metal in period 3 having valency 3.
Fill in the blanks from the words A to F given below’.
A: Decreases
B: Increases
C: Remains same
D: Increases by one
E: Electropositive
F: Electronegative
Across a period from left to right in the Modern Periodic Table.
No. of electron shells _________; No. of valence electrons __________: Electronegativity increases Character of elements changes from electropositive to ________.
