Deuterium is a relatively uncommon form of hydrogen, but can be created from what common source? select one: a. coal b. air c. natural gas d. water

D. Water

Explanation:

Isotopes -

For some elements , there are various forms possible , which have different number of neutron and same number of protons , are referred to as the isotopes .

The three isotopes possible for the element hydrogen are -

Protium , Deuterium and Tritium .

Where ,

Deuterium is very rarely found on Earth , but can easily be prepared from water , which is known as deuterated water , which is helpful for isotopic labelling.

pure substance: iron,copper

impure substance: water,charcoal

answer: they produce more slow than unicellular organisms.