Number of electrons in the outer most shell of an atom determines its what ?

Which characteristics are typical of a human population in the postindustrial stage?

This is collection of data made by comparing objects in standard units. in science, the units are metric.

How do energy and matter move through an ecosystem? both energy and matter unidirectionally flow through an ecosystem. both energy and matter cycle within an ecosystem. matter unidirectionally flows through an ecosystem, whereas energy cycles within an ecosystem. energy unidirectionally flows through an ecosystem, whereas matter generally cycles within an ecosystem.