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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
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.
3Li, 14Si, 2He, 11Na, 15P Which of these elements belong to be period 3?
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?
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 group of this element?
Which pair of atomic numbers represents elements in the same group?
Find the odd one out and give its explanation.
Answer the following question in one sentence.
Write the name of the noble gas having 2 electrons in its valence shell.
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 |
| 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 element having stable electron configuration from the third period.
Write the name.
Highest electropositive element
Right or wrong sentence.
The elements lithium and beryllium are in the same period because their valencies are similar.
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.
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.
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.
