Which defines a codon? * a protein that begins transcription by breaking apart H bonds
three nucleotide bases on mRNA that specify one amino acid
the strong bond between two complementary nitrogen bases
a free-floating base that attaches to an open DNA strand

It is a three nucleotide based on RNA that specify one amino acid

is this for the e2020 class

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