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प्रश्न
Find the odd one out and give its explanation.
विकल्प
Potassium
Magnesium
Calcium
Beryllium
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उत्तर
Potassium
Explanation-
Potassium is placed in group 1 while others are placed in group 2 of the modern periodic table.
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संबंधित प्रश्न
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?
Write the scientific reason.
The third period contains only eight elements even though the electron capacity of the third shell is 18
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.
To which period does this element belong?
Which pair of atomic numbers represents elements in the same group?
Which among the following is the largest element?
Write the name of noble gas having 2 electrons in its valence shell.
Write the name of an element having electronic configuration 2,8,2.
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 number of electrons in the outermost shell of an atom determines the _______.
Write the name.
The element having stable electron configuration from the third period.
The elements lithium and beryllium are in the same period because their valencies are similar.
Beryllium and calcium are alkaline earth metals.
The number of shells decreases in a group from top to bottom.
Write scientific reason.
Boron and oxygen elements are placed in the second period in periodic table.
In group 2, beryllium and calcium elements, calcium is more electropositive element than beryllium.
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?
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.
