Which bond is formed due to a high electronegativity difference? covalent hydrogen metallic ionic

Ionic bond

Explanation:
When the electronegativity between the two atoms is very large (usually greater than 2.1), this can lead to total transfer of electron from the higher electronegative  atom to the lower one.
The total transfer of electrons leads to the formation of ionic bond.

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.