Home > Astronomy > Time Scale of the Cosmos

During which step in cosmic evolution were the chemical bases for life created?

Answer 1

Chemical evolution

A portion of the small molecules, like water or methane, formed in the interstellar medium; the remainder of the small molecules, and nearly all of the more complex ones, formed on planets through chemical and photochemical reactions. Carbon, the building block of life, oxygen, and nitrogen were formed inside stars.

By signing up, you agree to our Terms of Service and Privacy Policy

Answer 2

Alexander Acosta

The chemical bases for life were created during the nucleosynthesis phase of cosmic evolution.

By signing up, you agree to our Terms of Service and Privacy Policy

Answer from HIX Tutor

When evaluating a one-sided limit, you need to be careful when a quantity is approaching zero since its sign is different depending on which way it is approaching zero from. Let us look at some examples.