mendeleev periodic law
Answers
Explanation:
Mendeleev's periodic law states that the physical and chemical properties of elements are a periodic function of their atomic weights. When the elements are arranged in order of their increasing atomic weights, elements with similar properties are repeated after certain regular intervals.
Mendeleev's periodic Law ✓
♦ Mendeleev's periodic table contains vertical columns called 'groups' and horizontal rows call 'periods'.
♦ There are in all eight groups, i.e., group I to group VIII. Each of these groups from I to VII is divided into two sub-groups : A and B. Group VIII has no sub group. Inert gases were not known at that time.
♦ All elements of a sub-group ( or of the group VIII, which has no sub-group) have similar properties and show the same valency, which is equal to the group number ( for upto Group IV ) or group number subtracted from eight ( for Groups V-VII ).
♦ In a period, elements gradually change from metallic to a non-metallic character or metallic character decreases as one moves from left to right across the horizontal row.
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