Answer:
Phosphorus-32
Step-by-step explanation:
Alfred D. Hershey and Martha Chase radiolabelled phosphorus as 32P and sulfur as 35S. This was done to observe if the radio labeled sulfur-containing protein coat or the radio-labeled P containing DNA enters the host cell. They showed that when the bacterial virus T2 infects Escherichia coli cells, the radioactive phosphorus-containing DNA of the viral particle enters the host cells. The host cells do not show the radio-labeled sulfur-containing protein of the viral coat. This proved that DNA, not the proteins is the genetic material.