A urethane is a molecule in which a carbonyl group is part of an ester and an amide (it is an amide in one direction, an ester in the other direction). It is formed from the reaction of an isocyanate with an alcohol. A polyurethane is a polymer formed between a diisocyanate and a diol. Draw curved arrows to show the movement of electrons in this step of the mechanism of the formation of a polyurethane. Arrow-pushing Instructions

answer: the figure is attached herewith.

step-by-step explanation:   we are given to sketch a unit circle and label the terminal points corresponding to

in the attached figure, we have drawn a unit circle, with centre at o(0,0) and radius 1 unit. we have labelled the points a, b, c, d and e corresponding to the angles below

∠aox = 60°,

∠box = 120°,

∠cox = 180°,

∠dox = 240°,

∠eox = 300°.

and the coordinates are a(0.5,1), b(-0.5,1), c(-1,0), d(-0.5,-1) and e(0.5,-1).

thus, the answer is complete.

a electronegativity decreases beacuse the size of nucleus is bigger.