Atoms

Atomic Structure and Isotopes

Relative: Subatomic particles have tiny masses so use relative masses instead of grams. • Electron: An electron has about 1/ 1800th mass of a proton, positioned in the shell. • Protons: Number of protons identifies element- atomic number, the number on top in periodic...

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Relative Masses

Relative Mass: No units as it is ratio of two masses- it’s relative. • Carbon-12 Isotope: One atom of carbon 12 is 12 atomic mass units. 1 atomic mass unit is 1/12th of an atom of carbon- 12 = mass of a proton or neutron. • Relative Isotopic Mass: It is the mass of an...

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Formulae and Equations

Ion Charges: Group 1 = 1+ ions etc. Group 7 = 1-. • Need to know also Zn2+ and Ag+ . • Transition Metals: Form several ions with different charges. Ionic charge shown with Roman numeral in name. • Binary Compound: Compounds containing two elements. For the second...

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