Two European physicists and an American chemist received Nobel science prizes yesterday for fundamental and far-reaching discoveries -- and new technologies -- involving the forces of nature hidden within the atom and the building blocks of life itself.

The 1984 Nobel prize in chemistry went to R. Bruce Merrifield, the first American to win a Nobel this year. The 63-year-old professor at New York's Rockefeller University was cited by the Royal Swedish Academy of Sciences for an "ingenious" method of chemical synthesis that revolutionized the development of new drugs and gene technology.

The Nobel physics prize will be shared by Carlo Rubbia of Italy, 50, and Simon van der Meer of the Netherlands, 59, for their "decisive contributions" to a large research effort in Geneva that led to last year's dramatic discovery of new particles believed to carry one of the four basic forces in the universe.

These "W" and "Z" particles provided experimental evidence for "weak interaction," a force that is responsible for some types of radioactive decay and nuclear processes that control the power of the sun.

The award honors not only the two individuals but the effort by the European nuclear research organization known as CERN to develop a superaccelerator that could isolate these subatomic particles. The facility, located on the Franco-Swiss border, is funded by 12 member nations.

Yesterday's announcement is a reminder that in the highly competitive world of high-energy physics, U.S. scientists' dominant world position has been eroded or even supplanted -- at least temporarily -- by the well-funded efforts of European colleagues.

Many American scientists have warned for years that cuts in research budgets dating back to the early 1970s were threatening American leadership in numerous areas of science. The prestigious Nobels, the top world prizes in the sciences, have been one measure of that leadership, but there is often a lag of many years between the original research and the awards themselves.

Merrifield's chemistry award, for laboratory synthesis of peptide and protein molecules, was for a method developed largely in the late 1950s and '60s. It later became a basic laboratory tool with widespread medical and research applications.

Recognition for the European physicists was unusually quick, since the new CERN superaccelerator went into operation in l981 and the discoveries of the new particles were announced only last year.

The Nobel committee said it was honoring Rubbia for conceiving the experiment and carrying it out and van der Meer for the invention that made it possible. The experiments entailed the development of a giant atom-smasher in which beams of subatomic particles called protons and their counterparts, antiprotons, could race around in opposite directions.

The collision, like two cars crashing head-on, created greater force than existing accelerators, in which a single beam was directed against a stationary target.

Rubbia's 1983 announcement of the discovery of two types of W particles and a Z particle thought to carry the "weak force" helped provide proof for a theory proposed by 1979 Nobel laureates that linked the weak force with the electromagnetic force involved in electric charges.

It was a step toward proving the so-called "unified field theory" linking together all four forces in the universe. The other two physical forces are gravity and the strong force involved in nuclear reactions.

U.S. scientists noted yesterday that Rubbia, who divides his time between CERN and an appointment at Harvard University, had sought to do similar experiments in this country at the Fermilab in Batavia, Ill., but was hampered in part by a lack of funding.

Fermilab's associate director, Dr. James Bjorken, said the U.S. lab now is building a new colliding beam accelerator that is expected to be operational in l986 and will produce higher power than the CERN facility.

"They're now in the lead, but we're catching up fast," said Phillip Schewe of the American Institute of Physics.

The United States has held a stronger lead in the world of biochemistry in which Nobel winner Merrifield works. The Texas-born researcher, who gets much of his funding from the National Institutes of Health, noted in a telephone interview yesterday that his research didn't require the costly "massive equipment" used by physicists.

Merrifield's research involved the development of a laboratory technique for putting together small units called amino acids into peptide chains. Peptides join together to make up proteins, which are essential to all living things. There are only about 20 amino acids, but they can be combined in a virtually unlimited number of ways.

Merrifield devised a simple, automated technique for synthesizing peptides on a routine basis in large quantities that "greatly stimulated progress in biochemistry, molecular biology, pharmacology and medicine," said the Nobel committee.

Merrifield said yesterday that his own work continues, with his biggest laboratory creation a synthetic version of the natural compound interferon which is 166 amino acids long. He learned of the award from an excited laboratory assistant when he arrived for work yesterday morning "five minutes late," accompanied by his wife, Libby, who works in his laboratory.

He said "it came as a total surprise. My first reaction was not to believe it."