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प्रश्न
Find the period in which these elements can be placed.
4Be, 17Cl, 2He, 13Al
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उत्तर
- 4Be- Electronic configuration is (2, 2). It is placed in period 2.
- 17Cl- Electronic configuration is (2, 8, 7). It is placed in period 3.
- 2He- Electronic configuration is (2). It is placed in period 1.
- 13Al- Electronic configuration is (2, 8, 3). It is placed in period 3.
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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.
7N, 6C, 8O, 5B, 13Al Which is the most electronegative element among these?
Write the scientific reason.
The third period contains only eight elements even though the electron capacity of the third shell is 18
An element has its electron configuration as 2,8,2. Now answer the following questions.
i. What is the atomic number of this element?
ii. What is the valency of this element?
iii. What is the group of this element?
iv. To which period does this element belong?
v. With which of the following elements would this element resemble?
`_7N , _4Be , _18Ar , _17CL`
An element has its electron configuration as 2, 8, 2. Now answer the following question.
What is the atomic number of this element?
An element has its electron configuration as 2, 8, 2. Now answer the following question.
Which of the following elements would this element resemble?
(Atomic numbers are given in the brackets)
N(7), Be(4), Ar(18), Cl(17)
Find the odd one out and give its explanation.
Match the columns.
| Column A Electronic configuration |
Column B Valency |
| 1) 2, 2 | a) 1 |
| 2) 2, 8, 1 | b) 2 |
| 3) 2, 5 | c) 3 |
| d) 5 |
Match the columns.
| Column A | Column B |
| 1) Alkaline earth metals | a) Group 18 |
| 2) Alkali metals | b) Group 17 |
| 3) Halogen | c) Group 2 |
| 4) Noble gas | d) Group 1 |
| e) Group 14 |
The number of electrons in the outermost shell of an atom determines the ______.
Write the name.
The element having stable electron configuration from the third period.
Write the name.
Highest electropositive element
Right or wrong sentence.
The valency of the elements in group 2 is 1.
Beryllium and calcium are alkaline earth metals.
Right or wrong sentence.
The number of shields decreases as the calculation goes down from top to bottom.
Write an explanation.
Group
Distinguish between:
Group - Period
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?
- Which elements have the same column?
- 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?
