Each of the insoluble salts below are put into 0.10 M hydrobromic acid solution. Do you expect their solubility to be more, less, or about the same as in a pure water solution ? Clear All silver bromide copper(II) hydroxide iron(II) sulfide More soluble than in pure water. Similar solubility as in pure water. Less soluble than in pure water.

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. 

3is your answer to yuor question

Elements that have complete valence shells are found in group 18, also known as the noble gases. these gases possess the stable octet, and are neon, radon, xenon, etc.