All particles attract other particles due to mass, this law is the heart of modern physics to some degree and what most understand gravity as.

So the mass of Earth should attract the particles that make up the gases, hydrogen, nitrogen, helium and oxygen in our atmosphere then.

Yet the mass of Earth has no gravitational effect on gases that are composed of particles.

Gases are created by the biosphere that is earth, by reducing matter to it’s most simple elements being gases and then these gas elements are released to form the Earth’s atmosphere.  Earth’s atmosphere is trapped by an electronic field, it’s why Elon Musk is wrong as to terraforming Mars. The core of Mars is depleted as to an electronic field strong enough to trap a sustaining atmosphere and it’s why those gases bled through Mars atmosphere and Mars is now a pretty dead rock even though at one times it had a rich atmosphere. Today dry lake, river and ocean beds are clearly evident on Mars and a minor atmosphere even still exists that is incapable of supporting life as we understand it. Although remnants of life should exist as extreme life forms in the soil and in the minor frozen pole areas that still exist. Life has a way of forming and existing even in the most harsh environments on molecular levels and also even in simple insect life forms found in deep areas of soil.

If Universal Gravity existed the gases couldn’t gather in an electronic field creating an atmosphere, since the particles of gases would be forced to earths surface and not create the atmosphere we have. So the electronic field that forms the Ionosphere above the atmosphere traps gases and eventually when this magnetic field is diminished as happened on Mars our own atmosphere will bleed into space and complex surface life as we know it will not be able to exist on Earth.