You look at the atomic mass.. The number of neutrons is different for different individual atoms of the same element, each atom is also known an isotope. Looking at a periodic table, the atomic mass listed is the average atomic mass for all isotopes of that element found in nature.
Answer:
K=CHANGE IN CONCENTRATION/TIME TAKEN
Explanation:
One day (24 hours), because one rotation of earth on its axis is the position of the countries to the sun shifting, thus resulting in the periods of sun and moon, (the day and the night).