In the film, lavoisier said that the mass gained by the pipe plus the mass of the collected gas "exactly" equaled the lost mass of water. if we believe lavoisier to have behaved scientifically, how must you interpret that statement?

hmmmm let me think about that

n has four pairs of electrons in the valence shell, electrons repel one another ,n has 7 protons in its nucleus, and since n has 7 protons, it must fill the second shell, giving it 4 pairs of electrons. the electrons form 3 bonds and 1 lone pair of electrons. each pair of electrons repels the other pairs, so they are equally far apart.

so all of the above