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

41382 Views

See similar Chemistry GCSE tutors

Related Chemistry GCSE answers

All answers ▸

How do I calculate the relative formula mass of Calcium carbonate (CaCO3)


Explain why potassium is more reactive than sodium, giving the balanced chemical symbol equation for the reaction of potassium and water.


Increaseing the pressure of a system will have what effect on the equilibrium of this reversable reaction 3H2 + N2 <---> 2NH3


What is a method that you can use for balancing equations?


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