How is the sea of electrons model is used to explain the physical properties of metals? electrons give off a charge, the greater or lesser the metal will depend on how packed the universe is in the metal, atoms and such.
Mutations can also be caused by exposure to specific chemicals or radiation. These agents cause the DNA to break down. This is not necessarily unnatural  even in the most isolated and pristine environments, DNA breaks down. Nevertheless, when the cell repairs the DNA, it might not do a perfect job of the repair.
If a mutation then occurs in the second copy of the susceptibility gene in one somatic cell, that cell begins to divide uncontrollably. As the cell divides, the offspring cells inherit these mutations and perpetuate the cancerous characteristics. Alternatively, two somatic mutations may occur spontaneously in the same cell. For example, exposure to ultraviolet wavelengths in sunlight, or to cancer-causing chemicals, can cause somatic mutations.