Beryllium-9 is the stable isotope of beryllium with relative atomic mass 9.012182, 100 atom percent natural abundance and nuclear spin 3/2.

Beryllium-9 is an isotope of the chemical element Beryllium, which, in addition to the element-specific 4 protons, has 5 neutrons in the atomic nucleus, resulting in the mass number 9. 9 Be is a primordial nuclide on Earth and the only stable nuclide of beryllium; It is therefore a monoisotopic element. See also: list of Beryllium isotopes.

Beryllium (4 Be) has 11 known isotopes and 3 known isomers, but only one of these isotopes (9 Be) is stable and a primordial nuclide. As such, beryllium is considered a monoisotopic element.

Detailed decay information for the isotope beryllium-9 including decay chains and daughter products.

BE9 or BE-9 may refer to: Beryllium-9 (Be-9 or 9 Be), an isotope of beryllium; Royal Aircraft Factory B.E.9, a British aircraft of World War I

Introduction Low energy measurements of the Be9 (y, n) reaction, performed using radioactive gamma ray sources, indicate a sharp peak in the cross section just above threshold 1, 2).

The Royal Aircraft Factory B.E.9 was a British experimental reconnaissance aircraft of World War I. The intention of the designers was to combine the high performance of tractor configuration aircraft with a good field of fire for the observer's machine gun, as provided by pushers.

Ditaoni Ho do hamatean Mambaen di ahu hangoluan.

A BE-9 survey must be completed in its entirety by U.S. offices, agents, or other representatives of foreign airline operators that transport passengers or freight and express to or from the United States, whose total covered revenues or total covered expenses were $5 million or more during the previous year, or are

Beryllium is a monoisotopic element and its atomic weight is determined solely by its isotope 9 Be. The Commission last revised the standard atomic weight of beryllium in 2013 based on the latest Atomic Mass Evaluation by IUPAP.