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प्रश्न
Right or wrong sentence.
The valency of the elements in group 2 is 1.
पर्याय
Right
Wrong
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उत्तर
The given sentence is wrong.
Explanation:
The valency of elements in Group 2 (the Alkaline Earth Metals) is 2, not 1.
- Reasoning: Elements in Group 2 have two electrons in their outermost shell (valence shell). To achieve a stable noble gas electron configuration, they readily lose these two electrons to form ions with a charge of + 2 (e.g., Mg2 +, Ca2+).
- Contrast: Elements in Group 1 (the alkali metals) have one electron in their outermost shell, which gives them a valency of 1.
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.
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.
4Be, 6C, 8O, 5B, 13Al Which is the most electropositive element among these?
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.
What is the group of this element?
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)
______ is the outermost shell for elements of period 2.
Find the odd one out and give its explanation.
Answer the following question in one sentence.
Write the name of an element having electronic configuration 2,8,2.
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 |
The number of electrons in the outermost shell of an atom determines the ______.
Right or wrong sentence.
The number of shields decreases as the calculation goes down from top to bottom.
Write an explanation.
Group
Identify periods of elements and blocks of elements from given electronic configuration.
- 2, 8, 2
- 2, 8, 7
- 2, 1
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.
