The closer the charged objects are, the stronger the electrostatic force.  Will was pulling some magnets apart. When is the electrostatic force the lowest when the magnets are close or when the magnets are far?
when the magnets are far

Because these isotopes decay more slowly, they can be used to date much older specimens.  Ron is trying to figure out how old some isotopes are. The isotopes are decaying very slowly, so they are likely specimens that are older or younger?
older

Genotypes with greater fitness produce more offspring and pass more copies of their alleles to the next generation.  A genotype with good fitness will likely produce more or less offspring than a more fit one?
more