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प्रश्न
Identify periods of elements and blocks of elements from given electronic configuration.
- 2, 8, 2
- 2, 8, 7
- 2, 1
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उत्तर
| Electronic configuration |
Period | Block | |
| i. | 2, 8, 2 | 3 | s - Block |
| ii. | 2, 8, 7 | 3 | p - Block |
| iii. | 2, 1 | 2 | s - Block |
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संबंधित प्रश्न
An element has its electron configuration as 2, 8, 2. Now answer the following question.
a. What is the atomic number of this element?
b. What is the group of this element?
c. To which period does this element belong?
d. With which of the following elements would this element resemble? (Atomic numbers are given in the brackets)
N(7), Be(4), Ar(18), Cl(17)
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 down the electronic configuration of the following elements from the given atomic numbers. Answer the following question with explanation.
4Be, 6C, 8O, 5B, 13Al Which is the most electropositive element among these?
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?
Write down the electronic configuration of the following elements from the given atomic numbers. Answer the following question with an explanation.
13Al, 14Si, 11Na, 12Mg, 16S
Which of the above elements has the highest metallic character?
Write down the electronic configuration of the following elements from the given atomic numbers. Answer the following question with explanation.
6C, 3Li, 9F, 7N, 8O Which of the above elements has the highest nonmetallic character?
Which of this element belong to the period 3? Write their electronic configuration
`3^(Li) , 14^(Si) , 2^(He) , 15^(P)`
An element has its electron configuration as 2, 8, 2. Now answer the following question.
What is the group of this element?
Which pair of atomic numbers represents elements in the same group?
Find the odd one out and give its explanation.
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 |
Right or wrong sentence.
The number of shields decreases as the calculation goes down from top to bottom.
Write a scientific reason.
In group 2, beryllium and calcium elements, calcium is more electropositive element than beryllium.
Complete the following chart.
| Shell | n | 2n2 | Electron holding capacity |
| K | 2 × 12 | 2 | |
| L | 2 | 8 | |
| 3 | 2 × 32 | 18 | |
| N | 4 | 2 × 42 |
Find the period in which these elements can be placed.
4Be, 17Cl, 2He, 13Al
Electronic configuration of element A is 2,8,1. Answer the following questions based on this information.
- What is the atomic number of element A?
- Find the group to which this element belongs.
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.
- Which block does nonmetals belong to?
- Write name of any two metalloid elements.
What is the electronic configuration of K19?
An element has its electron configuration as 2, 8, 1. Now answer the following questions:
- What is the atomic number of this element?
- What is the group of this element?
- To which period does this element belong?
