Lithium has two naturally occurring isotopes, lithium-6 and lithium-7. Use °les to represent protons and squares to represent neutrons. Draw the nucleus of each isotope.
a) °le with 3 squares, °le with 4 squares
b) °le with 3 squares, °le with 3 squares
c) °le with 4 squares, °le with 3 squares
d) °le with 4 squares, °le with 4 squares