1. Note the average atomic mass of the elements on the nano-balance. Add atoms to the larger balance until it registers the same number (in g) as the reading on the nano- balance (in u). Use the Exponent slider to help get the correct amount. Stop adding atoms when the readings on both balances match exactly Element
CU
C
S
AL
Atomic mass (units)
How many atoms did you need to add?

I'm not sure but i will try to find out

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. 

Ametal with a large number of free flowing electrons most likely has good conductivity