Does h2o have carbon

What is 'h2o' ???? If you mean 'H2O'. , then there is NO carbon present in the molecule.

'H2O' means that there are two atoms of the element , hydrogen (H) and one atom of the element , oxygen (O), combined together to form the molecule H2O (Water).

NB When writing chemical symbols , single letter symbols are ALWAYS a CAPITAL letter, hence hydrogen (H), not (h) similarly, oxygen (O) ,not (o).

This is the internationally recognised standard for chemical symbols.

NNB Carbon has the chemical symbol 'C' . So if this does NOT appear in the molecule, then it does not contain carbon.