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Unit 1.4 The Periodic Table
Bell WorkBell Work•Are properties of a compound the same as the elements in the compound? Why?
•How Small is an Atom?
Agenda1.Turn in Properties of Compounds WS2.Bell Work3.Good Things4.Videos5.Periodic Table Coloring (NEED COLORED PENCILS)
Introduction to the Periodic Table
• How was the Periodic Table formed?-TED Talk Video
• Work on the Periodic Table Coloring Assignment• You will be able to use your periodic table on all tests and quizzes• DO NOT WRITE ANYTHING ON YOUR PERIODIC TABLE UNLESS I ASK YOU TO
Developing the Periodic Table
• Dmitri Mendeleyev wanted to organize the elements by similar properties• Reactivity: How easily an
element will combine with other substances to form new compounds
Creating the Periodic Table
• Organized elements of similar reactivity together• Organized elements that create
similar compounds together• Placed lighter elements on the top,
increased mass as you moved to the right and as you moved down
Periods vs. Groups • Periods: Horizontal Rows• Main group elements• Transition elements• Lanthanides• Actinides
• Groups: Vertical Columns• 1: Alkali Metals• 2: Alkaline Earth Metals• 3-12: Transition Metals• 17: Halogens• 18: Noble Gases
Valence Electrons• Electrons in the outer orbital or “Shell” of an atom• These are the electrons that react to form bonds between
elements• Elements want a “Full Valence Shell” which is 8• 8 valence electrons = unreactive• Elements can gain and lose electrons to get to 0 or 8 valence electrons
• A Tour of the Periodic Table Video
Periods • Periods are numbers 1-6• This equals the
number of orbitals for the electrons• Example:• Period 1 all have 1
orbital• Period 2 has 2• Period 3 has 3
orbitals
Groups
• Groups can be numbered in 2 ways (1-18) and (1-8- this excludes the transition metals)• If we exclude the transition metals, then the period #=
#valence electrons
Property Trends of the Periodic Table
• At room Temperature, most elements are solid• Several are gases• Only a few are
liquid
Property Trends of the Period Table• Metals: Most elements, on the
left of the chart, conduct heat and electricity, shiny, malleable• Nonmetals: on the right of the
chart, poor conductors• Metalloids: on the stair step,
both metal and nonmetal properties
Property Trends of the Periodic Table
• Reactivity:• Elements in the upper right
explode with metals• Elements in the lower left
explode with water• Elements in the middle are not
very reactive• Noble Gases are very
UNREACTIVE
Alkali Metals
•Alkali Metals in Water Videos•Group 1 (Li, Na, Rb, Cs, Fr)• 1 Valence electron, wants 0 = VERY REACTIVE•Shiny, soft, highly reactive metals
Alkaline Earth Metals
• Less reactive than Alkali Metals• 2 Valence Electrons • Shiny, silvery-white, soft• Mg, Be, Ca, Sr, Ba, Ra
Halogens
• F, Cl, Br, I, At• 7 Valence Electrons = VERY REACTIVE
Noble Gases
• Unreactive Gases (Full valence shell, all 8 electrons)• He, Ne, Ar, Kr, Xe, Rn• Fluorescent
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