atomic mass number Flashcards
1
Q
what is a isotope
A
same element different number of neutrons
2
Q
where is the mass number of a element and what is it
A
the bottom number
ATOMIC NUMBER is the number of PROTONS in a nucleus. e.g. carbon atoms always have 6 protons. An ATOM must also have this number of ELECTRONS in order to be neutral. If not it is an ION instead.
2
Q
where is the mass number of a element and what is it
A
the top number
MASS NUMBER (or RELATIVE ATOMIC MASS/RAM/Ar) is the number of PROTONS + NEUTRONS in a nucleus. So this Carbon-12 atom must have 6 neutrons.
3
Q
how to calculate the average mass of an element
A
average = total mass of 100 atoms
mass ———————–
100
