HELP HELP 3. What theory describes how mitochondria and chloroplasts were derived from the relationship between the first eukaryotic cells and smaller prokaryotes?
A the theory of spontaneous generation C the theory of natural selection
B the plate tectonic theory D the endosymbiotic theory

i need

hydrogen is a compound or a single element and a element is a pure substence that cannot be separated into simpler subtances

clorine is a compound its a chemical substance that forms when two or more different elements combine

so both hydrogen and clorine are compounds

50% lit on the left side

i think the answer is composed of atoms