Scientists use patterns in the periodic table to what?

I found this on google

“The periodic table is important because its is organized to provide a great deal of information about elements and how they relate to one another in one-easy-to-use reference. The table can be used to predict the properties of elements, even those that have not been discovered.”

I hope this helps

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.