Question

elements in a group generally posses similar properties but elements along a period have different properties. How do you explain this statement

Answer 1

Because they are arranged in the similarity of properties in group number and not in the periods

Answer 2

Answer:

According to the modern periodic table the Physical and chemical properties of the elements are periodic functions of their atomic numbers. It means, when the elements are arranged in the order of their increasing atomic numbers or electronic configuration.

That means the element having same valance electronic configuration has similar properties and on going down the group electronic configuration is same. Therefore elements in a group possess similar properties.

But the valance electron configuration of different element in a same period is different, so the properties of different element in a same period are  different.  Elements in the same group of the periodic table have similar properties because their electronic configurations have the same number of electrons in the outermost shell