You can heat it or apply pressure.
I am assuming that you mean mass of an object. The answer is no, it does not change. Mass (Density) stays the same wherever the object is, only its weight will change if the force of gravity is different.
No
To change density there are three ways. You can change the shape, mass or volume of the object
Yes.
density
In a simple way, since density = mass /volume, the density of an object can be changed by changing either mass or volume of an object .
The density of an object is determined by its mass and volume. If the mass of the object increases and its volume stays the same, the density will increase. If the volume of the object increases and the mass stays the same, the density will decrease.
Changing the shape CAN change the density. If you change it into a smaller shape, then you increase the density. However the mass will not change.
density is how dense an object is (see dense) it is calculated by dividing the mass by volume of an object. density can be changed by changing the size or shape or the object
Density is a property that depends on the mass and volume of the object, not its shape. Changing the shape of an object does not alter the amount of mass or volume it contains, so the density remains the same.
Adding heat to the object if the object is a solid.
No, changing the shape or size of an object does not change its density. Density is determined by the mass of an object divided by its volume, so as long as the mass and volume remain constant, the density will stay the same.