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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) and Chlorine (Cl) are nonmetals. Argon (Ar) is an inert gas element and is not classified as a metal, nonmetal or metalloid. - Nonmetals belong to 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.
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?
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.
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)
_______ is the outermost shell for elements of period 2.
Which pair of atomic numbers represents elements in the same group?
Which among the following is the largest element?
Find the odd one out and give its explanation.
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 |
The number of electrons in the outermost shell of an atom determines the _______.
Write the name.
The group of elements having electronic configuration 2, 2.
Beryllium and calcium are alkaline earth metals.
Write an Explanation.
Group
Write 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
