When you add milk, sugar and coffee to a cup of hot water, which of these explain that what you formed in a mixture? A new substances is formed B. You can no longer taste the sugar
C. You can still taste the bittemess of the coffee, the sweetness of the sugar and the creaminess of the milk
D. Each of the part of the mixture changed in color, amount in taste

Ci think not

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.