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Day 2 The Periodic Table. Sci 10 Chemistry. Try creating your own Periodic Table. Look at the cards of the first 18 elements. Can you group them in a way that makes sense?.
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Day 2 The Periodic Table Sci 10 Chemistry
Try creating your own Periodic Table • Look at the cards of the first 18 elements. Can you group them in a way that makes sense?
Mendeleïev created the modern periodic table of the elements, placing the elements in order of increasingatomic mass.
Look back at your Periodic Table • Look at all of the models of elements in a Period (→) • What do they all have in common? • Look at all of the models of elements in a Group (↓) • What do they all have in common?
Columns (vertical) of the periodic table are calledGROUPS • Elements in a group sharecharacteristics and propertiesbecauseall have same # of electrons on outershell • Rows (horizontal) of the periodic table are calledPERIODS • Elements in a period all have the sameamount of electronshell(s)
Metals and non-metals have differentproperties. • Metalloids have properties of metals and non-metals.
Hydrogen – an exception • It can behave like an alkaline metal or like a halogen
Back to electrons… • Electrons are located on shells around the nucleus • Different shells contain different number of electrons • Different elements have different numbers of shells • Valence shells: shell the farthest away from nucleus • Valence electrons : electrons on the valence shell
Period # indicates the # of electron shells: • Period 1 – 1 shell (2 e- max) • Period 2 – 2 shells : • shell #1 - 2 e- max • Valence shell (shell #2) – 8 e- max • Period 3 – 3 shells : • shell #1 - 2 e- max • shell #2 – 8 e- max • Valence shell (shell #3) – 8 e- max
Bohr-Rutherford Diagram/ Electron shell diagram An atomic model that shows the distribution of ALL electrons • Indicate the # of p+ and # of neutrons in nucleus (drawn as a circle) • Determine # of shells (# of period) • Add electrons (max 2 for the 1st, 8 for the 2nd and 8 for the 3rd)
Group # represents the # of valence electrons • (number of electrons in outer shell) • If group # greater than 10, subtract 10 to find the # of valence electrons
Lewis Structures/ Electron Dot Diagrams • A method of representing an atom that shows only its valence electrons sodium carbon chlorine
Practice! • p.97 #15, 18, 19 • Day 2 - Questions