I will take a stab at it, but there are not equations, did you forget them?
The answer:
for the monoatomic <span>selenium ions
</span> -the ion charge of selenium is 2-, so the answer is [Se]2+
as for the monoatomic phosphorus ions
-the ion charge of phosphorus is 3-, so the answer is [P]3-
The appropriate answer is a. HUNTER-GATHERER. Hunter-gatherer societies are nomadic and they forage for edible plants, bean, fruits and nuts. They also hunt wild game for food. Early humans in the Neolithic period practiced this way of life.
Agrarian societies thrive on agriculture which they depend on for sustainable and for trade. Animals and plants are domesticated and so people can settle and build a society. Pastoral agriculture is a semi-nomadic lifestyle where the society is centered around keeping herds of grazing animals. Industrial societies focus on manufacturing and this is the backbone of the society.