The Periodic Table By Dianne Cellini EdS
Periodic Table Probe • Assemble the puzzle. On your own paper: • Describe, in detail, what you think the missing pieces include. • Draw a picture of what you think the missing pieces should look like, include shape, size and color in your drawing. • Explain how you were able to determine what the missing pieces should look like. • Compare your drawing to the actual missing pieces. How did you do? • How did patterns help you determing the look of the missing pieces?
How was the Periodic Table created? • Science is the search for patterns in nature. • In the 1800’s, many scientists noticed patterns in the properties of different elements.
Look at the following elements, what patterns do you notice? Element Atomic # Atomic Radius Ionization H 1 37 1300 He 2 50 2380 Li 3 152 520 Be 4 111 900 B 5 88 800 C 6 77 1100 N 7 70 1400 Na 11 186 480 Mg 12 160 700 Al 13 143 600 Si 14 117 800 P 15 110 1010
Who discovered the patterns? • Dimitri Mendeleev • Introduced a chart summarizing the known properties of the elements to his students. • The chart resembles a calendar.
What did the original Periodic Table look like? • Arranged the original 60 elements in order by their increasing masses. • Left blanks because he predicted there were missing elements.
Ponder this: • Was the great organization of the periodic table invented by humans or discovered by humans? Explain.
How is the PTE arranged? • by the type of element (substance) • by the state of the element (solid, liquid, or gas). • the mass of the element (what we think of as “weight”).
GROUPS Vertical columns Similar properties among the elements Have the same # of electrons in outer shell (valence electrons) Group 1-used in the making of soaps Group 2-fire resistant Group 11-precious metals Group 17-tendency to form salts Group 18-unreactive gases How is the PTE organized?
PERIODS Horizontal rows Same number of energy shells (where the electrons are) Period 2 Li Be B C N O F and Ne All have 2 energy shells More on how the PT is organized:
Quick Review! • The PTE is an arrangement of what? • The elements are arranged in increasing _________& ___________. • The PTE has columns called________. • The PTE has rows called___________.
More review! • Groups • Vertical ________on the PTE. • Have __________ properties because of the same number of __________ in the outer shell. • Those are called v_______ electrons • Periods • Horizontal _______ on the PTE. • All elements in the same row have the same # of e______ s______.
Another way the periodic table is organized: • Metals • Non-Metals • Metalloids
Metals Neodymium • 85% of known elements • Shiny • Opaque • Good conductors of electricity • Good conductors of heat • Malleable-can be molded • Ductile-can be drawn into wires • All but a few are solid at room temperature (ex: Mercury) • Located to the left of zig zag
Non-Metals Carbon • On the right side of the zig zag line. • Dull • Non-conductors of heat & electricity • Brittle, will shatter when hammered • At room temperature some are solid, some are liquid, some are a gas • Reactive solids
Metalloids Germanium • Between metals and non-metals, along zig zag line • Weak conductors of heat and electricity • Used for semi conductors (conducts w/ higher temps) • Take on the properties of their group • If closer to the metals-have more metal properties • If closer to non-metals-take on those properties Boron
Metal, non-metal or metalloid? • Leah has an element that is silvery gray, solid, brittle and is a semi conductor. • What is it?
Metal, non-metal or metalloid? • Tommy has an element that is shiny, solid, can be pulled into wire(ductile) and is a good conductor of heat and electricity. • What is it?
Metal, non-metal or metalloid? • Michael has an element that is a yellow solid that crumbles and does not conduct heat or electricity. • What is it?
Atomic Number-the number of electrons or protons Symbol Name Atomic mass-protons plus neutrons What’s in the rectangles? 11 Na sodium 22.98
What is the atomic number? 8 What is the symbol? O What is the name of the element? oxygen What is the atomic mass? 15.99 Practice reading the Periodic Table: 8 O oxygen 15.99
What is the atomic number? 79 What is the symbol? Au What is the name of the element? gold What is the atomic mass? 196.97 Practice reading the Periodic Table? 79 Au gold 196.97
From the information on the periodic table, we can find the number of electrons, protons and neutrons. Atomic number equals the protons or electrons. Atomic mass minus the atomic number equals the number of neutrons. How do you use the Periodic Table?
How many protons? 11 How many electrons? 11 How many neutrons? 22.98 -11.00 11.98 Practice finding the # of electrons, protons and neutrons. 11 Na sodium 22.98
How many protons? 8 How many electrons? 8 How many neutrons? 15.99 - 8.00 7.99 Practice finding the # of electrons, protons and neutrons. 8 O oxygen 15.99
How many protons? 79 How many electrons? 79 How many neutrons? 196.97 - 79.00 117.97 Practice finding the # of electrons, protons and neutrons. 79 Au gold 196.97