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प्रश्न
An element has its electron configuration as 2, 8, 2. Now answer the following question.
What is the atomic number of this element?
The electronic configuration of an element is 2, 8, 2. Then write the answer to the question given below.
What is the atomic number of this element?
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उत्तर
The atomic number of this element is 12.
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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.
11Na, 15P, 17Cl, 14Si, 12Mg Which of these has largest atoms?
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`
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.
Which of the following elements would this element resemble?
(Atomic numbers are given in the brackets)
N(7), Be(4), Ar(18), Cl(17)
Find the odd one out and give its explanation.
Answer the following question in one sentence.
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 |
The number of electrons in the outermost shell of an atom determines the ______.
Right or wrong sentence.
The valency of the elements in group 2 is 1.
Right or wrong sentence.
The elements lithium and beryllium are in the same period because their valencies are similar.
Write an explanation.
Group
Write a scientific reason.
Boron and oxygen elements are placed in the second period in periodic table.
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
Identify periods of elements and blocks of elements from given electronic configuration.
- 2, 8, 2
- 2, 8, 7
- 2, 1
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.
