Question

which is the property of gas would you use to fill up a cycle tyre tube

Answer 1

Drivers prefer Nitrogen over natural air mainly because Nitrogen molecules are larger, so they can't escape through the tire which is made of rubber which is a porous substance and density of nitrogen is also high, hence the pressure varies less with the variation in temperature.

Answer 2

Now a days drivers prefer nitrogen gas to be filled up a cycle tyre tubes.