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प्रश्न
Write the scientific reason.
The third period contains only eight elements even though the electron capacity of the third shell is 18
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उत्तर
- The current periodic table consists of seven horizontal rows, known as periods. Periodic elements are ordered in increasing order of atomic numbers. The third row consists of 8 elements, with an electron capacity of 18.
- During the third period, the atomic number and number of electrons in the shell rise as you move left to right. The number of elements in the third period is determined by electronic configuration and the octet rule.
Argon (Ar) is the final element of the third period with a maximum capacity of 18 electrons. The octet of electrons is full, and because argon belongs to the zero group, the third shell has 18 electrons.Atomic No. 11 12 13 14 15 16 17 18 Elements Na Mg Al Si P S Cl Ar
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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.
11Na, 15P, 17Cl, 14Si, 12Mg Which of these has largest atoms?
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)`
______ is the outermost shell for elements of period 2.
Find the odd one out and give its explanation.
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 Electronic configuration |
Column B Valency |
| 1) 2, 2 | a) 1 |
| 2) 2, 8, 1 | b) 2 |
| 3) 2, 5 | c) 3 |
| d) 5 |
Write the name.
The element having stable electron configuration from the third period.
Right or wrong sentence.
The valency of the elements in group 2 is 1.
Write a scientific reason.
In group 2, beryllium and calcium elements, calcium is more electropositive element than beryllium.
Find the period in which these elements can be placed.
4Be, 17Cl, 2He, 13Al
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.
- Which type of elements X and Y are metals, nonmetals or metalloids?
- From which block the elements X and Y are?
- Determine the electronic configuration and valency of these elements.
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.
An element has its electron configuration as 2, 8, 1. Now answer the following questions:
- What is the atomic number of this element?
- What is the group of this element?
- To which period does this element belong?
