Dr. Henry Meyer Rosenstock, 54, a senior scientist at the National Bureau of Standards who specialized in physical chemistry, died Sept. 14 near Lisbon, Portugal, following a heart attack. He was attending a NATO Advanced Study Group when he was stricken.

Dr. Rosenstock, who lived in Bethesda, was born in Mannheim, Germany. He came to this country in 1936 and settled in New York City. He graduated from the College of the City of New York and earned a doctorate at the University of Utah.

He was a chemist at the Oak Ridge National Laboratory in Oak Ridge, Tenn., until 1956, when he moved to this area. He worked for private companies in this area and Baltimore until the 1960s, when he joined the National Bureau of Standards.

His work at NBS included research on molecular ionization, reactions in gaseous systems and mass spectrometry. From 1963 to 1979, he directed the agency's Ion Energetics Data Center.

Dr. Rosenstock was the author or co-author of more than 70 papers published in technical journals. He also wrote or contributed to five books. He was a cofounder of the American Society for Mass Spectrometry.

Survivors include his wife, Shirley of Bethesda, and three sons, Stephen of Los Angeles, and Paul and Peter, both of Bethesda.