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The flexi disc (also known as a phonosheet, Sonosheet or Soundsheet, a trademark) is a phonograph record made of a thin, flexible vinyl sheet with a molded-in spiral stylus groove, and is designed to be playable on a normal phonograph turntable.
With a production order of 10.5 million, it became the largest single press run of any record at the time. [citation needed] 7 inch (17 cm) Between 1892 and 1900, the Berliner Gramophone Company released 7" records, to be played with a recently upgraded Gram-O-Phone reproducing machine.
Clear evidence of the presence of 26 Al at an abundance ratio of 5×10 −5 was shown by Lee et al. [18] [19] The value (26 Al/ 27 Al ~ 5 × 10 −5) has now been generally established as the high value in early Solar System samples and has been generally used as a refined time scale chronometer for the early Solar System. Lower values imply a ...
Isotope half-lives. The darker more stable isotope region departs from the line of protons (Z) = neutrons (N), as the element number Z becomes larger. Isotopes are nuclides with the same number of protons but differing numbers of neutrons; that is, they have the same atomic number and are therefore the same chemical element. Isotopes neighbor ...
Only five stable nuclides contain both an odd number of protons and an odd number of neutrons. The first four "odd–odd" nuclides occur in low mass nuclides, for which changing a proton to a neutron or vice versa would lead to a very lopsided proton–neutron ratio (2 1 H, 6 3 Li, 10 5 B, and 14 7 N; spins 1, 1, 3, 1).
A push-button telephone is a telephone that has buttons or keys for dialing a telephone number, in contrast to a rotary dial used in earlier telephones.. Western Electric experimented as early as 1941 with methods of using mechanically activated reeds to produce two tones for each of the ten digits and by the late 1940s such technology was field-tested in a No. 5 Crossbar switching system in ...
The stable nuclide 206 Pb has Z = 82 and N = 124, for example. For this reason, the valley of stability does not follow the line Z = N for A larger than 40 (Z = 20 is the element calcium). [3] Neutron number increases along the line of beta stability at a faster rate than atomic number.
Iron-55 (55 Fe) is a radioactive isotope of iron with a nucleus containing 26 protons and 29 neutrons. It decays by electron capture to manganese-55 and this process has a half-life of 2.737 years. The emitted X-rays can be used as an X-ray source for various scientific analysis methods, such as X-ray diffraction .