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प्रश्न
K, Pb, Ca, Zn (In the increasing order of the reactivity)
उत्तर
Pb Zn Ca K
APPEARS IN
संबंधित प्रश्न
The atomic masses of three elements A, B and C having similar chemical properties are 7, 23 and 39, respectively.
- Calculate the average atomic mass of elements A and C.
- Compare the average atomic mass with atomic mass of B.
- What could the elements A, B and C be?
The position of eight elements in the Modern Periodic Table is given below where atomic numbers of elements are given in the parenthesis.
| Period No. | ||
| 2 | Li(3) | Be(4) |
| 3 | Na(11) | Mg(12) |
| 4 | K(19) | Ca(20) |
| 5 | Rb(37) | Sr(38) |
(i) Write the electronic configuration of Ca.
(ii) Predict the number of valence electrons in Rb.
(iii) What is the number of shells in Sr?
(iv) Predict whether K is a metal or a non – metal.
(v) Which one of these elements has the largest atom in size?
(vi) Arrange Be, Ca, Mg and Rb in the increasing order of the size of their respective atoms.
Why does the size of the atoms progressively become smaller when we move from sodium (Na) to chlorine (Cl) in the third period of the periodic table?
Which of the following element does not lose an electron easily?
(a) Na
(b) F
(c) Mg
(d) Al
What is modern periodic law?
State whether the following statement is true or false
On moving horizontally across a period, number of valence electrons increases from one to eight.
Select the correct answer
Identify the metalloid
State the number of elements in period 1, period 2 and period 3 of the periodic table.
Arrange the following in order of increasing radii:
Mg2+, Mg, Mg+
The position of elements A, B, C, D and E in the periodic table are shown below:
|
Group 1 |
Group 2 |
Group 17 |
Group 18 |
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|
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|
D |
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|
B |
C |
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A |
|
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E |
State which is most reactive (i) metal (ii) non-metal
