Why do the atomic radii of the elements decrease across a period on the periodic table.

It may seem counterintuative that as the elemets' atomic numbers increase their atomic radii decrease. This is due to the increased electrostatic attraction (coulombic interaction) between nucleus and valence electrons. As long as elements are all in the same period then all thier valence electrons are in the same energy level, so there is no increase in the atomic radius due to fillig a new outer shell. This means the dominant effect is simple the electrostatic interaction. As the atomic number increases so does the interaction force, hence the atomic radius decreases.

Answered by Daniel H. Chemistry tutor

2946 Views

See similar Chemistry A Level tutors

Related Chemistry A Level answers

All answers ▸

In the topic of transition metals, what are the different types of ligands and what in itself, is a ligand?


Calculate the pH of the solution formed when 30 cm3 of 0.150 moldm-3 aqueous sulfuric acid is added to 30 cm3 of 0.200 moldm-3 aqueous potassium hydroxide at 25 C.


Please give the definition of Le Chatilier's principle. Use this to explain what would happen if you increased the temperature of an equilibrium in which the forwards reaction is exothermic.


Describe the structure and bonding of benzene.


We're here to help

contact us iconContact usWhatsapp logoMessage us on Whatsapptelephone icon+44 (0) 203 773 6020
Facebook logoInstagram logoLinkedIn logo

© MyTutorWeb Ltd 2013–2025

Terms & Conditions|Privacy Policy
Cookie Preferences