Starting in 1850 when Europe become industrialized, the frequency of melanic forms of the peppered moth in populations until they made up of some population.

increased; almost 100%

Explanation:

The peppered moth witnessed a change in its color and the number at the end of the eighteenth century. The reason behind this was the Industrial Revolution that led to an increase in air pollution. With the increase in air pollution, the dark-colored moths increased in the number. Later, when air pollution decreased, the light-colored moths started to predominate. It was in 1895 that the number of dark-colored moths increased to the maximum.

sodium i think the chemical element of atomic number 11, a soft silver-white reactive metal of the alkali metal group.