Working as a summer student for the ministry of natural resources you are responsible for testing the water in a creek near an industrial site for the presence of
the toxic metal ions lead (II) and mercury (II) in the water. Design an experiment to
sequentially test for the presence of lead (II) and mercury ions as well as the non-toxic
magnesium ion. Assume the water sample does not include any other interfering ions.
Show the net ionic equations for the precipitation reactions that might occur.

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. 

Iam not going to tell you

Wow that a lot of text for my tiny so i no wanna answer

27. =3,500,000 x 4,000 = 14,000,000,000