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The three families that are found in the center portion of the periodic table are the Iron group, the Cobalt group and the nickel group. There are 18 families in the periodic table.
Three families are found in the center portion of the periodic table are of iron, cobalt and nickel atoms.
What are groups in periodic table?
Groups are the vertical columns of elements present in the periodic table in which elements of same valency and valence configuration is present.
In the periodic table total 18 groups are present starting from left side to right side. In the middle of the periodic table three families or groups of iron, cobalt and nickel atoms are present which are known by the name of group 8th, 9th and 10th of the periodic table.
So, three families are of iron, cobalt and nickel atoms.
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