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