A measure of the number of particles of a substance in a given volume would be concentration. <span>In chemistry, </span>concentration<span> is the abundance of a constituent divided by the total volume of a mixture. There are a number of ways expressing it such as molarity, molality, normality, ppm, percentage and the like.</span>
A 15-month-old child, equivalent to a child of 1 year and 3 months of age, should have began weaning from bottle feeding from 6 months of age. Tooth decay or dental caries are commonly associated with prolonged bottle feeding as the sugars and other substances in milk; when drank from a teat from a bottle; prolongs the exposure of teeth to the milk, leading to overgrowth of bacteria causing dental caries.
Essential amino acids refer to the eight amino acids the adult body needs, which they cannot be synthesized correctly or at all.
The essential amino acids must be obtained from food such as proteins (meats, seafood, milk, eggs, etc).
Biologists do not fully understand DNA because there are constant changes and new discoveries developing.
