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प्रश्न
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.
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उत्तर
| Elements of 2nd row of modern periodic table | ||||||||
| Name | Lithium | Beryllium | Boron | Carbon | Nitrogen | Oxygen | Fluorine | Neon |
| Valency | 1 | 2 | 3 | 4 | 3 | 2 | 1 | 0 |
| Atomic number | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 |
|
Electronic |
2, 1 | 2, 2 | 2, 3 | 2, 4 | 2, 5 | 2, 6 | 2, 7 | 2, 8 |
Elements in ascending order of atomic mass:
Lithium < Beryllium < Boron < Carbon < Nitrogen < Oxygen < Fluorine < Neon
APPEARS IN
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.
7N, 6C, 8O, 5B, 13Al Which is the most electronegative 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?
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 atomic number of this element?
Find the odd one out and give its explanation.
What determines the chemical reactivity of elements?
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 |
Write the name.
Highest electropositive element
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.
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
Distinguish between:
Group - Period
Identify periods of elements and blocks of elements from given electronic configuration?
- 2, 8, 2
- 2, 8, 7
- 2, 1
XY compound is formed by X (Atomic number 11) and Y (Atomic number 17), then answer the questions given below.
- Determine the position of the element X and Y periodic table.
- X and Y belongs to which of the following: metals, nonmetals or metalloids?
- From which block the elements X and Y are?
- Determine the electronic configuration and valency of these elements.
What is the electronic configuration of K19?
