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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) and Chlorine (Cl) are nonmetals. Argon (Ar) is an inert gas element and is not classified as a metal, nonmetal or metalloid. - Nonmetals belong to 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.
19K, 3Li, 11Na, 4Be Which of these atoms has smallest atomic radius?
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.
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 among the following elements would lose an electron easily?
Which among the following is the largest element?
Find the odd one out and give its explanation.
Find the odd one out and give its explanation.
Match the columns.
| Column A | Column B |
| 1) s -block | a) Lanthanides and actinides |
| 2) p -block | b) Group 3 to 12 |
| 3) d -block | c) Group 1, 2 |
| 4) f -block | d) Group 13 to 18 |
| e) Zero group |
Match the columns.
| 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 |
The number of electrons in the outermost shell of an atom determines the _______.
The elements lithium and beryllium are in the same period because their valencies are similar.
Write scientific reason.
Boron and oxygen elements are placed in the second period in periodic table.
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 | ______ |
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.
Distinguish between:
Group - Period
Make a chart which shows the name of the element, valency, atomic number, electronic configuration in the 2nd row of the modern periodic table and arrange these elements in ascending order of atomic mass.
