Scientest distinguish whether an entity is living or non living by describing of life

They can distinguish whether the entity is living or non living by checking whether they have all the seven characteristics of living things.

These 7 characteristics include:

Movement

Respiration

Sensitivity

Growth

Reproduction

Excretion

Nutrition.

If the entity does show all these seven characteristics, it should be a living organism.

In the past, scientists by using these 7 characteristics, they sorted living things in 5 kingdoms (plus virus), each with their own other characteristics.