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1 Atomic structure and periodic table.pptx
- 1. structure and periodic table recap LearningObjectives: 1 Identify the information of an element from the periodic table. Predict the characteristics and how atoms would act from information derived from the periodic table
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- 3. How are elementsdifferent if they are all made of atoms? Where do atoms come from? What does period and group tell us?
- 4. What information isprovided by the key? Mass number = ? Chemical notation is A ZX
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- 7. Isotopes Two or moreforms of the same element that contain equal numbers of protons but different numbers of neutrons in their nuclei.
- 8. Relative Atomic Mass Themass number is shown on the Periodic table as the relative atomic mass (Ar). Relative atomic mass (Ar) is the weighted average mass of all isotopes of an element relative to the mass of carbon 12 It is measured in the units amu (atomic mass units) which is equal to 1/12 the mass of a single atom of carbon 12 (the most abundant isotope of carbon, 1.660538921 × 10 −24 gram). An average atomic mass of all the isotopes is taken.
- 9. Relative Atomic Mass Isotopicabundance determined through mass spectrometry. To calculate RAM, multiply each isotope mass by its % abundance, add them all up and divide by 100. https://phet.colorado.edu/sims/html/isotopes-and-atomic-mass/latest/isotopes-and-atomic-mass_ all.html
- 10. Practice questions 1. Rubidiumhas two common isotopes, 85 Rb and 87 Rb. If the abundance of 85 Rb is 72.2% and the abundance of 87 Rb is 27.8%, what is the average atomic mass of rubidium? 2. Titanium has five common isotopes: 46 Ti (8.0%), 47 Ti (7.8%), 48 Ti (73.4%), 49 Ti (5.5%), 50 Ti (5.3%). What is the average atomic mass of titanium? Challenge : Silicon has three stable isotopes, 28 Si, 29 Si and 30 Si. The heaviest isotope has a percentage abundance of 3.1 %. Using the relative atomic mass from the periodic table, calculate the percentage abundance of the lightest isotope to one decimal place. 10
- 11. How do wecalculate the relative atomic mass from a mass spectrum? The mass spectrum of boron: 80% 20% 11
- 12. Quick check Calculate therelative atomic mass of magnesium. 12
- 15. • Transition metals 35metals found in the middle of the Periodic Table that are very good conductors. • Alkali metals Metals found in group 1 of the Periodic Table, that are silvery in color, soft and very reactive. • Alkali-earth metals Metals found in group 2 of the Periodic Table, silvery white in color but not as reactive as group 1 metals. • Halogens Non-metals found in group 17 on the Periodic Table and form salts when combined with metals and are toxic. • Noble gasses Gases found in group 18 on the Periodic Table that are very stable, and almost never react with other elements. Why does these groups of elements have similar characteristics?
- 16. Niels Bohr Designed theatomic model we use today to simplify many concepts.
- 17. Period Group • Groups =number of Valence electrons (electrons in the outer shell) • Periods = number of Energy levels
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