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प्रश्न
Write down the electronic configuration of the following elements from the given atomic numbers. Answer the following question with explanation.
11Na, 15P, 17Cl, 14Si, 12Mg Which of these has largest atoms?
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उत्तर
11Na, 15P, 17Cl, 14Si, 12Mg
Electronic configuration of the following elements is:
11Na = 2,8,1
15P = 2,8,5
17Cl = 2,8,7
14Si = 2,8,4
12Mg = 2,8,2
11Na has largest size among these because according to the trend, atomic radius decreases as we move from left to right in a period of the periodic table. The atomic number of elements increases which means the number of protons and electrons in the atoms increases. Due to large positive charge on the nucleus, the electrons are pulled closer to the nucleus and the size of atom decreases.
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संबंधित प्रश्न
Write down the electronic configuration of the following elements from the given atomic numbers. Answer the following question with explanation.
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Write the scientific reason.
The third period contains only eight elements even though the electron capacity of the third shell is 18
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What is the atomic number of this element?
_______ is the outermost shell for elements of period 2.
Which pair of atomic numbers represents elements in the same group?
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| Column A | Column B |
| Electronic configuration |
Valency |
| 1) 2, 2 | a) 1 |
| 2) 2, 8, 1 | b) 2 |
| 3) 2, 5 | c) 3 |
| d) 5 |
Write the name.
Highest electropositive element
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Write an Explanation.
Group
In group 2, beryllium and calcium elements, calcium is more electropositive element than beryllium.
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4Be, 17Cl, 2He, 13Al
Write name of elements, symbol, atomic number, electronic configuration of second period in modern periodic table?
Observe the given chart and answer the questions given below.
| Element | A | B | C | D |
| Electronic configuration | 2, 1 | 2, 8 | 2, 8, 1 | 2, 8, 8 |
- Which elements are in the same row?
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- Which elements are in the 18th column?
- Which element is more reactive among A and C?
- Which of the following elements A or B will form compounds?
Observe the periodic table given below and write the answers of the questions.

- Write the name and valencies of the elements in 3rd row.
- Classify the elements in this row as metal, nonmetal and metalloids.
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- Write name of any two metalloid elements.
