Which of the following is true about ionic bonding ? It’s mostly formed between electrons on the left side of the periodic table
Lithium fluoride is formed by iconic bonding

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. 

Adialysis unit requires 78.5 l of water.the estimated digit is 5. 

Idon't mean to be a smart alec, length of atoms' bonds is the simplest way to define it.