The table shows the mass numbers and abundances of naturally occuring copper isotopes.
What is the relative atomic mass to 1 decimal place?
An atom of phosphorus has the symbol
Give the number of protons, neutrons and electrons in this atom of phosphorus:
A. Number of protons []
B. Number of neutrons [[15.97]]
C. Number of electrons []
The mass number of an atom is worked out by what?