Question

why does atomic size increases down the group but decreases along A period from left to right​

Answer 1

Answer:

Explanation:

As elements are placed in an ascending order of no. of electrons.

----> Therefore, atomic size inc down a group

Since electron affinity increases across the period, it pulls the electrons closer

hence decreasing atomic radius.

---> Therefore, atomic size decreases across a period

Answer 2

Answer:

Explanation:down the group electron negativity decreases so the screening effect also decreases hence increasing the atomic size but along the group electron negativity increases due to which the screening effect also increases and finally decreasing the atomic size