Explain why there is a general increase in the first ionisation energy across the third period.

The first ionisation energy depends on:the charge on the nucleus, the distance of the outer electron from the nucleus, the amount of shielding by inner electrons and whether the electron is alone in an orbital or part of a pair of electrons. In the whole of Period 3 the outer electrons are in the third shell so they are at similar distances from the nucleus and receive approximately the same amount of shielding from the first and second shells. The main difference is the increase in atomic number (number of protons) across the period. This causes greater attraction between the nucleus and the outer electrons, thus increasing the first ionisation energy.

MP
Answered by Mara P. Chemistry tutor

5943 Views

See similar Chemistry A Level tutors

Related Chemistry A Level answers

All answers ▸

Why is the melting temperature of Magnesium higher than that of Sodium?


Arrange the following elements in order of increasing ionization energy. Give an explanation. a) K, Cs, Na b) F, N, Be


Describe the trend in ionisation energies down group 1.


4.00 g metal carbonate, MCO3 reacts with acid to liberate a gas that occupies 0.5878 dm3 at 25˚C and 2.0 x 105 Pa. Identify the group 2 metal, M. Info: R = 8.314 J K-1 mol-1


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