Utilisateur
units of quantities must be subjected to the same math rules as other numbers
in × cm/in =cm
+
heavy +
No charge
Orbit around nucleus, - charge
is its mass number IE total number of protons in and neutron
it is an averge between 2 isotopes
bottom
top right
top left
place mass number as superscript in top left of element symbol "Mg
they have different nubers of neutrons.
