Questions

They are the sites at which microtubules attach to chromosomes.

Electronegativity is the tendency for an atom to attract electrons. There are general trends on the periodic table which you can use to determine the relative electronegativity for different elements, but otherwise you can also look at their valence shell and effective nuclear charge to determine their relative electronegativity.

Here from the given options, Lithium has least tendency to attract electrons and thus has a lower electronegativity.

Materials that allow electricity to flow are called electrical conductors and that materials which does not allow electricity to flow are called Insulators.