What is the relation between acceleration due to gravity and the radius of earth

In Newton’s equation for gravity, r^2 is in the denominator. So, if the radius of the earth decreases the gravitational pull would be stronger. If the radius increases, gravity will be weaker. The magnitude of the acceleration due to gravity is partly reliant on the distance between two objects.

There is a lot more to this, but it isn’t from Newton. You’d have to learn about general relativity from Einstein. Not directly from Einstein, because he kinda dead.

Magma  is composed of molten rock and is  stored  in the earth's crust. lava is  magma  that reaches the surface of our planet through a volcano vent.