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प्रश्न
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.
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उत्तर
- The elements in the third period are Sodium, Magnesium, Aluminium, Silicon, Phosphorus, Sulphur, Chlorine and Argon. Their valencies are 1, 2, 3, 4, 3, 2, 1 and 0, respectively.
- Sodium (Na), Magnesium (Mg) and Aluminium (Al) are metals. Silicon (Si) is a metalloid. Phosphorus (P), Sulphur (S), Chlorine (Cl) and Argon (Ar) are nonmetals.
- Nonmetals belong to the p-block.
- Two metalloid elements: Silicon and Germanium.
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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.
1H, 7N, 20Ca, 16S, 4Be, 18Ar Which of these elements belong to the second group?
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 explanation.
19K, 3Li, 11Na, 4Be Which of these atoms has smallest atomic radius?
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 question.
What is the group of this element?
An element has its electron configuration as 2, 8, 2. Now answer the following question.
To which period does this element belong?
______ is the outermost shell for elements of period 2.
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 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 |
Write the name.
The group of elements having electronic configuration 2, 2.
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 a scientific reason.
In group 2, beryllium and calcium elements, calcium is more electropositive element than beryllium.
Distinguish between:
Group - Period
What is the electronic configuration of K19?
