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From the periodic table, we find that it has 29 protons. The mass number (65) is the sum of the number of protons and neutrons. Therefore, we can subtract the number of protons from the atomic number to get the number of neutrons: # n = A – Z = 65 – 29 = 36.
29 lip 2022 · Determine the number of protons and electrons in an atom. Write and interpret symbols that depict the atomic number, mass number, and charge of an atom or ion. Define the atomic mass unit and average atomic mass
Potassium selenite | HKO3Se | CID 23677934 - structure, chemical names, physical and chemical properties, classification, patents, literature, biological activities, safety/hazards/toxicity information, supplier lists, and more.
10 sie 2015 · Selenium’s most stable allotrope is the hexagonal and crystalline form. Three main oxidation states of selenium are found: selenide (−2), selenite (+4) and selenate (+6). Selenium’s atomic mass is 78.963 and shows six stable and twenty-four radioactive isotopes.
The number of protons in an atom is called its atomic number (\(Z\)). This number is very important because it is unique for atoms of a given element. All atoms of an element have the same number of protons, and every element has a different number of protons in its atoms.
Atomic or ionic charge = number of protons − number of electrons. An atom that gains one or more electrons will exhibit a negative charge and is called an anion. Positively charged atoms called cations are formed when an atom loses one or more electrons. For example, a neutral sodium atom (Z = 11) has 11 electrons.
Therefore, the atomic number also indicates the number of electrons in an atom. The total number of protons and neutrons in an atom is called its mass number (A). The number of neutrons is therefore the difference between the mass number and the atomic number: A – Z = number of neutrons.
