You would expect an earthworm to have no exoskeleton because as you see it is very flexible and soft. Organisms with such have body parts that are divided and an earthworm do not have any visible parts on them also having an exoskeleton would not allow an organism to move like an earthworm does.
The change in foot shape making the feet wider and longer than the hands and the curvature of the spine also adapted to it
<span>If it loses that 1 electron (0 electrons, 1 proton, 1 neutron) it become an ion that is positively charge because it has more protons than electrons. [Ignore the neutrons] </span>
<span>If it gains an electron (2 electrons, 1 proton, 1 neutron) it becomes an ion that is negatively charge because it has more electrons than protons </span>
<span>A molecule - when 2 or more "different" elements combine or when 2 or more of the "same" elements combine </span>
<span>1 proton 1 electron <----- that is considered to be neutral </span>
<span>3 protons, 3 electrons <----- neutral </span>
<span>5 protons 5 electrons <----- neutral </span>
<span>6 protons, 5 electrons <-- positive ion [more protons than electrons] </span>
<span>5 protons, 8 electrons <--- negative ion [more electrons than protons] </span>
