What criteria do we use to decide whether something is alive

Explantation-

There are certain features, which we use to define whether something is alive or not-

Growth- Increase in mass, and increase in number is the two characteristics of growth. In the case of living organisms, growth is internal, and it is external in non-living things, So, Growth is not considered the defining feature of a living organism.

Reproduction-Power of producing new ones from the existing species. Reproduction can be sexual or asexual. In the case of single-celled organisms, growth and reproduction are synchronous. As in amoeba single cell undergoes fission to produce two new daughter cells. So, reproduction cannot be considered the defining feature of the living organism.

 Metabolism- The total of all reactions (catabolic and anabolic) proceeding simultaneously is known as metabolism. Metabolism cannot be seen in the non-living organism. So, metabolism is considered as defining feature of the living organism.

A cellular organization-All living organism is made up of cells, they are the structural and functional unit of a living organism, cellular make-up is absent in non-living things. So, the cellular organization is considered as defining feature of the living organism.

Consciousness- The ability of an organism to sense the external environment is seen in the living organism only. So, Consciousness is considered as defining feature of the living organism.

Final Answer-

Growth
Reproduction
Metabolism
Cellular-organization
Consciousness
criteria we use to decide whether something is alive or not.