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Question
Two elements P and Q belong to the same period of the modern periodic table and are in group 1 and group 2, respectively. Compare the following characteristics in the tabular form.
- Number of electrons in their atoms
- Their tendency to lose electrons
- Their metallic characters
- Formation of their oxides
- Formulae of their chlorides
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Solution
As elements P and Q belong to the same period of the modern periodic table and are in group 1 and group 2, they belong to alkali metals and alkaline earth metals, respectively.
| Characteristic |
P |
Q |
|
(a) Number of electrons in their atoms |
Valence electron = 1 |
Valence electrons = 2 |
|
(b) Their tendency to lose electrons |
Can easily lose electrons |
They will lose electrons easily but not as easily as alkali metals can. |
|
(c) Their metallic characters |
P is more metallic |
Q is less metallic than P |
|
(d) Formation of their oxides |
React rapidly with oxygen in the air 4Na + O2 → 2Na2O |
Less reactive than alkali metals |
|
(e) Formulae of their chlorides |
NaCl, KCl, CsCl |
MgCl2, CaCl2, BaCl2 |
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