Will a balloon of nitrogen gas go up in air?

Density of air vs. nitrogen gas at NTP (normal pressure and temperature): * Air: 0.075 * Nitrogen: 0.0727 The fact that they are so close isn't surprising, as Mr. Kulkarni points out, because nitrogen is the major component of air. read more

In the case of a helium balloon, helium is so much lighter than air (composed of mainly nitrogen and oxygen) than it displaces very large amount of air compared to its overall mass. This creates an upward force which lifts the balloon up. However, you can't practically still lift houses though. read more