my guess is B. I am probably wrong
Answer:
Demography is the statistical study of human populations. Demography examines the size, structure, and movements of populations over space and time. It uses methods from history, economics, anthropology, sociology, and other fields.
Answer:
One
Explanation:
Sodium (Na) has one valence electron so it gets one dot.
Answer:
a green pigment, present in all green plants and in cyanobacteria, responsible for the absorption of light to provide energy for photosynthesis. Its molecule contains a magnesium atom held in a porphyrin ring.