Question

what is atomic radii and how it variate in a period?​

Answer 1

Answer:

The atomic radius of atoms generally decreases from left to right across a period. ... Within a period, protons are added to the nucleus as electrons are being added to the same principal energy level. These electrons are gradually pulled closer to the nucleus because of its increased positive charge.

Answer 2

Answer:

Atomic radius of the elements generally decreases from left to the right in a period because on moving from left to right in aperiod the nuclear charge gradually increases by one unit & one electron is also added in the electron shell.Due to  this the electrons get attracted more & more towards the nucleus.consequently the atomic radii decreases .

Atomic radius of the elements increases as we move downwords in a group because on moving down a group there is an increase in principal quantum number & thus, increase in the number of electrons shells.Therefore the atomic size is expected to increase

Explanation:

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