Rapid extraction of Hydrogen from the atmosphere?

I have found information on the internet that points to the magnetic fields of the galaxy, stars and certain planets will enable a spacecraft to be driven by a magnetic drive. Energy would be obtain by fusing the gases found in space, hydrogen into helium and then oxygen...

Pure hydrogen exists as H2 molecules. These molecules are too low mass to be effectively retained by the earth's gravity, so any molecular hydrogen in the atmosphere drifts off into space.

When hydrogen is needed, it is obtained by chemical methods from other compounds, i.e. by splitting water with electricity.

Alchemy was once popular, but with the advent of modern chemistry and physics, it has become clear that atoms can be changed from one to the other only under rare circumstances, i.e. uranium decays into lead. I don't think there is any way that nitrogen could be converted into hydrogen.

As for space travel, getting things out of the atmosphere isn't so difficult; probably the biggest problems have to do with the engineering necessary to make safe and durable habitats that can support life.

You can't 'split atoms of nitrogen to get hydrogen'.

The only hydrogen in the atmosphere is in the water vapor. So the only way to get hydrogen out of the atmosphere is to break up water molecules. It is easier to do this with liquid water.

It isn't clear what link this has to rocket weight.

to get fuel on the go?

even if you had this ability, it wouldnt help a lot in space travel, since there is not a lot of hydrogen to fuel your ship in space