14. Total number of protons and neutrons in an atom of a given isotope MASS NUMBER
15. Mass Number Mass number is the number of protons and neutrons in the nucleus of an isotope. 8 8 18 18 Arsenic 75 33 75 Phosphorus 15 31 16 Nuclide p + n 0 e - Mass # Oxygen - 10 - 33 42 - 31 15
21. How many electrons and how many neutrons does the atom have? 19 F 9
22. How many electrons and how many neutrons does the atom have? 19 F 9 number of neutrons = mass # - at. # A= 19 Z = 9 = 10 neutrons # of neutrons = A- Z # of neutrons = 19 - 9
27. All atoms of the same element do not necessarily have the same number of neutrons in their nuclei
28. Atoms of the same element that have different number of neutrons ISOTOPES
29. Isotopes…Again (must be on the test) Isotopes are atoms of the same element having different masses due to varying numbers of neutrons . Isotope Protons Electrons Neutrons Nucleus Hydrogen–1 (protium) 1 1 0 Hydrogen-2 (deuterium) 1 1 1 Hydrogen-3 (tritium) 1 1 2