Question
Question: In periodic table, the metallic character of elements : A. increases, (i) from left to right acros...
In periodic table, the metallic character of elements :
A. increases, (i) from left to right across a period and (ii) on descending a group
B. decreases, (i) from left to right across a period and (ii) on moving up group from bottom to top
C. increases from left to right across a period and decreases on descending a group
D. increases from left to right across a period and increases on descending a group
Solution
We know that metallic character of any element is related to the tendency of elements to lose electrons in a chemical reaction. Elements are placed in periodic tables in such a manner that they follow a trend of metallic character while moving left to right, right to left in a period or bottom to top or top to bottom in a group.
Complete step by step answer:
When we move across a period from right to left in the periodic table, the metallic character of elements decreases. This happens because atoms of elements across a period from right to left accept electrons more readily to fill their valence shell.
Metallic character increases as we move down a group in periodic table. The reason behind the increase of metallic character down the group is that when we move down in a group the atomic radius of elements increases and the elements lose electrons very easily as there will be less attraction between the nucleus and the valence electron because of their large radius. Hence option B and D are the correct options that is In periodic table, the metallic character of elements decreases, (i) from left to right across a period and (ii) on moving up group from bottom to top or increases from left to right across a period and increases on descending a group.
So, the correct answer is “Option B and D”.
Note:
1- Hence on moving across a period from left to right metallic character of elements goes on decreasing as the atomic size decreases. Thus the metals are placed on the left of the periodic table.
2- In the same way metallic character of elements decreases on moving up in a group from bottom to top.