Primary amines can be prepared from nitriles by reduction with lialh4. the two-step sequence involves sn2 displacement of halide ion by cyanide ion followed by reduction, and yields a primary amine with one more carbon than was present in the alkyl halide. draw curved arrows to show the movement of electrons in this step of the mechanism.

Mass is the amount of matter in an object.  weight is the measurement of the pull of gravity on an object.  say for example, you travel to the moon which has a different gravitational field compared to the gravitational field of earth. (gravitational fields: earth = 1, moon = 0.165)  now when you are on the moon, the pull of gravity on you is different than on the earth. and as weight is the measurement of the pull of gravity on an object, that means yes, your weight can and will change on the moon.  however, on the moon, on earth or even on jupiter, the amount of mass inside of you remains the same. meaning your physical mass remains constant.  in conclusion it is possible for your weight to change as your mass remains constant. 

The total number of nucleons

The answer for this is a