What do the numbers mean at the side of an element in the periodic table?

The top number is the total mass number, particles in an atom of an element that have mass are protons and neutrons. So the top number tells us how many protons and neutrons there are in an atom of that element. The bottom number is the proton number, it is simply the number of protons in an atom of the element.

CN
Answered by Charlotte N. Chemistry tutor

41717 Views

See similar Chemistry GCSE tutors

Related Chemistry GCSE answers

All answers ▸

Show the covalent bonding in terms of electrons in their outer shell for a molecule of Carbon Dioxide


Explain the trends in first ionisation energy in the second period in the periodic table.


The composition by mass of a compound is: C=36.4%, H=6% and F=57.6%. Calculate the empirical formula. If the RFM is 66, what is the molecular formula?


Explain in terms of structure and bonding why graphite conducts electricity.


We're here to help

contact us iconContact ustelephone icon+44 (0) 203 773 6020
Facebook logoInstagram logoLinkedIn logo

© MyTutorWeb Ltd 2013–2025

Terms & Conditions|Privacy Policy
Cookie Preferences