That is the correct scansion for that line - the poem is written in dactylic hexameter - and the stressed and unstressed syllables don't alternate. The patterns of stressed and unstressed syllables alternate, but in this case, the pattern is X / /, not X / or / X. The best guideline is to say the line normally and be patient.
An isobar refers to all of the nuclides of all elements that have a particular atomic mass. For example, helium-6 is one of the many isotopes of helium. The isobars of helium-6 are hydrogen-6, lithium-6, beryllium-6, and boron-6.
sidebar definition: The definition of a sidebar is a short bit of information alongside a longer story in a publication or online, or a discussion between lawyers and a judge where jurors can't overhear. (noun) An example of a sidebar is a more detai...