atomic mass number

atomic mass number : The mass number ( A), also called atomic mass number or nucleon number, is the total number of protons and neutrons (together known as nucleons) in an atomic nucleus. Because protons and neutrons both are baryons, the mass number A is identical with the baryon number B as of the nucleus as of the whole atom or ion. The mass number is different for each different isotope of a chemical element. This is not the same as the atomic number ( Z) which denotes the number of protons in a nucleus, and thus uniquely identifies an element. Hence, the difference between the mass number and the atomic number gives the number of neutrons ( N) in a given nucleus: N=A−Z. The mass number is written either after the element name or as a superscript to the left of an element's symbol. For example, the most common isotope of carbon is carbon-12, or 12 C, which has 6 protons and 6 neutrons. The full isotope symbol would also have the atomic number ( Z) as a subscript to the left....   More from Wikipedia

atomic mass number : The mass recorded by a mass spectrometer can refer to different physical quantities depending on the characteristics of the instrument and the manner in which the mass spectrum is displayed. The accurate mass (more appropriately, the measured accurate mass) is an experimentally determined mass..   More from Wikipedia

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  series, arranged in suggested viewing order, go to my website. For a playlist containing all the videos in this series, click here: www.youtube.com (1) Proton, neutrons, and electrons mass and charge. Atomic mass units and elementary charge units (2) Mass number (A), atomic number (charge number, Z) (3) Conventional symbolism for nucleii. Alpha, beta, and gamma particles (4) Alpha, beta, and gamma decay (5) Problems (6) Mathematics of radioactive decay; decay constant (lambda) (7) A problem ( ...

Question : What is the atomic number and atomic mass number for an isotope of Pm with 89 neutrons. Give two answers: first, the atomic number; then, the atomic mass number.

Answer : Atomic #: 61- {the number of the element (doesn't change with isotopes)} Atomic mass: 150- {the atomic # + the number of neutrons}..   More from Yahoo Answers

Question : When I look at the periodic table most of the elements have an atomic mass number that isnt a whole number. For example hydrogen's atomic mass is 1.00794. Since the atomic number is the number of protons and neutrons in the atoms nucleus, how can an atom have ".00794" of a proton or neutron?

Answer : Atomic mass number is indicating the amu value of the atom of any element. The number is actually the total of numbers of Proton and Neutron it has in its atom. Now number of Proton in a atom for any particular element is fixed but the number of Neutron is not fixed. An element can have different number of neutrons in different atoms of same element which is called Isotopes. The Atomic number we see is addition of number of proton and average of number of neutron. As this average is never a whole number, the atomic number is not a whole number...   More from Yahoo Answers