Complete the balanced equation for the reaction that occurs when formic acid (hcooh) dissolves in water. include the state of matter for all chemical species.

Your balanced equation for this reaction is:

HCOOH (aq) + H2O (aq) → HCOO- (aq) + H3O+ (aq)

So from the reaction, we can see when formic acid dissolved in water so H3O+ ions will be formed.
and we can see that it is a balanced equation as:
we have H atoms = 4 on both sides of the reaction
and C atoms = 1 atom on both sides of the reaction
and O atoms = 3 atoms on both sides of the reaction
So it is our final balanced equation of the reaction.

The answer to that would be magnesium

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.