Question

what is meant by periodicity of properties of elements ? why are the properties of elements placed in the same group of the perodic table similar

Answer 1

Answer:

Periodicity is the repetition of elements with similar properties when they are arranged according to their atomic no. in the periodic table.

all elements of the same group have the similar properties because because they have similar outer electronic configuration. for example, in group 17 ,halogens have the electronic configuration ns^2 np^7 .

as we move from left to right, size decreases, nuclear charge increases and hence the electrons feel more attracted towards the atom and hence the tendency to gain electrons increases. Halogens (group 17 elements) are the most electronegative with Fluorine being the highest.

Answer 2

Answer:

periodicity is trends or recurring variations in element properties with increasing atomic number

properties of elements of same group are similar as they have similar valency. valency is the one which decides the chemical properties of any given element

hope it helps you friend