Which best describes a compound? A. the simplest form of matter
B. an element that has changed state
C. a physical mixture of chemicals and elements
D. a chemical combination of two or more elements

D a chemical combination of two or more elements

D

Explanation:

I looked up the definition and it says

" a thing that is composed of two or more separate elements; a mixture."

a small container that holds a source of energy a solar cell that captures light energy and converts it into electricity a voltaic cell that uses the oxidation of a fuel to produce electricity

explanation:

if you mean hydrogen and oxygen then water is the product