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प्रश्न
Right or wrong sentence.
The valency of the elements in group 2 is 1.
विकल्प
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.
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 question.
What is the atomic number of this element?
Which among the following elements would lose an electron easily?
Which among the following is the largest element?
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.
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 |
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 |
Match the columns.
| Column A | Column B |
| 1) Alkaline earth metals | a) Group 18 |
| 2) Alkali metals | b) Group 17 |
| 3) Halogen | c) Group 2 |
| 4) Noble gas | d) Group 1 |
| e) Group 14 |
The number of electrons in the outermost shell of an atom determines the ______.
Write the name.
Highest electropositive element
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
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.
