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प्रश्न
The valency of the elements in group 2 is 1.
विकल्प
Right
Wrong
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उत्तर
The valency of the elements in group 2 is 1- Wrong
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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 the scientific reason.
The third period contains only eight elements even though the electron capacity of the third shell is 18
An element has its electron configuration as 2, 8, 2. Now answer the following question.
What is the atomic number of this element?
_______ is the outermost shell for elements of period 2.
Which pair of atomic numbers represents elements in the same group?
Find the odd one out and give its explanation.
Write the name of an element having electronic configuration 2,8,2.
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 elements lithium and beryllium are in the same period because their valencies are similar.
The number of shells decreases in a group from top to bottom.
Write an Explanation.
Group
In group 2, beryllium and calcium elements, calcium is more electropositive element than beryllium.
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
Write name of elements, symbol, atomic number, electronic configuration of second period in modern periodic table?
Observe the given chart and answer the questions given below.
| Element | A | B | C | D |
| Electronic configuration | 2, 1 | 2, 8 | 2, 8, 1 | 2, 8, 8 |
- Which elements are in the same row?
- Which elements have the same column?
- Which elements are in the 18th column?
- Which element is more reactive among A and C?
- Which of the following elements A or B will form compounds?
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.
