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प्रश्न
What determines the chemical reactivity of elements?
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उत्तर
The chemical reactivity of an element is determined by the number of valence electrons in it and the shell number of the valence shell.
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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.
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.
19K, 3Li, 11Na, 4Be Which of these atoms has smallest atomic radius?
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 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.
To which period does this element belong?
_______ is the outermost shell for elements of period 2.
Find the odd one out and give its explanation.
Write the name of noble gas having 2 electrons in its valence shell.
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 |
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 valency of the elements in group 2 is 1.
The elements lithium and beryllium are in the same period because their valencies are similar.
Write an Explanation.
Group
Write scientific reason.
Boron and oxygen elements are placed in the second period in periodic table.
In group 2, beryllium and calcium elements, calcium is more electropositive element than beryllium.
Distinguish between:
Group - Period
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.
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.
What is the electronic configuration of K19?
