Re: "kern", "kernel", "nucleus", "core"

Charles Riggs <chriggs@éircom.net> writes:

>>An atom has both a nucleus (the much smaller, positively charged body
>>that keeps it together & gives it most of its mass)
>
> The nucleus gives it most of its mass, but protons don't keep it
> together -- each having the same polarity of charge, they repel each
> other. Don't neutrons help keep all nuclei but hydrogen's together?

The antecedent of "that" is "body". The antecedent of "it" is
"atom". The nucleus keeps the atom together, by attracting the
electrons electrically.

The protons in the nucleus indeed repel each other electrically, but
are kept together, at least for a while, by the so-called strong
force, which the neutrons also exert. It works out that the strong
force cannot (quite) overwhelm the electrical repulsion unless there
are some neutrons in the mixture. On the other hand, if there are too
many neutrons, they are apt to decay, whereas protons are stable. It
works out that stable light nuclei have to have about as many neutrons
as protons, and stable heavy nuclei have to have more neutrons than
protons. These things are actually sort of understood, and 47 years
ago were actually sort of understood by me.
--
--- Joe Fineman joe_f@xxxxxxxxxxx

||: Who would not rather read a story about people catching fish :||
||: than a story about people eating fish? :||
.

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