An internal cost is a cost that is required to be able to produce a good and that have to be taken into account when establishing the price of the product. From the options given, the internal cost is the cost of employees (labor) as they perform the jobs necessary to manufacture the products that are sold by the company.
The other options are external costs that are cost that are not included in the price of the product but that have to be paid like contamination and the disposal of the product after its use.
Atoms of some elements pull more strongly on shared electrons than do atoms of other elements, as a result, the electrons are pulled more toward one atom, causing the bonded atoms to have a slight electrical charge.
