Why can’t we go to the center of the Earth?

The reason why we don't fall  to the center the earth is the same reason why we don't fall to the floor when you sit down in a chair; the electrons in your body repel the electrons in the chair. More specifically, there is an electron cloud around each nucleus.

Explanation:

in chemistry, a solution’s concentration is how much of a dissolvable substance, known as a solute, is mixed with another substance, called the solvent. the standard formula is c = m/v, where c is the concentration, m is the mass of the solute dissolved, and v is the total volume

the ratio of the conjugate base to the acid required to attain the desired ph.