If two substances combine to form a new substance with different properties it is called

The answer to your question is Compound

Explanation:

A Compound is a mixture of two or more elements that when combine gives to the new substance different properties from the original elements.

Examples of compounds

                    Elements                           Compounds

               Hydrogen   +   Oxygen   ⇒    Water

               Sodium       +   Chlorine  ⇒    Sodium Chloride

b..

is the correct one

explanation:

covalent bonds form as valence electrons are shared between two atoms. lewis structures and structural formulas are common ways of showing the covalent bonding in organic molecules. formal charge describes the changes in the number of valence electrons as an atom becomes bonded into a molecule.

b i think it’s a water wheel turning in a stream