The age of water or wine may be determined by measuring its radioactive tritium(3H) content. Tritium, present in a steady state in nature, is formed primarily by cosmicirradiation of water vapor in the upper atmosphere, and it decays spontaneously by a firstorder process with a half-life of 12.5 years. The formation reaction does not occursignificantly inside a glass bottle at the surface of the earth.

Calculate the age of a suspected vintage wine that is 20% as radioactive as a freshly bottled specimen. Radioactivity follows first order rate kinetics.

It shows that the experiment is designed properly.

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.