Explain why it is harder to remove an inner shell electrons than a valence electron from an atom

It makes sense that an inner shell electron would be tougher to remove than a valence electron because the inner shell electron is closer to the positive nucleus of the atom. Seeing as an electron caries a negative charge it would be too attracted to the positive core to leave readily. Also, the inner shell electrons are constantly repelling electrons outside of it's energy level (however the reason these electrons outside innershell energy levels don't simply fly away is the charge of the positive core overcomes the smaller charges of the comparably negligible inner shell electrons, but that repulsion is still there so keep that in mind)

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. 

No because it not possibly