Unit 1.4 The Periodic Table

Bell Work Agenda Turn in Properties of Compounds WS Bell Work Good Things Videos Periodic Table Coloring (NEED COLORED PENCILS) Bell Work Are properties of a compound the same as the elements in the compound? Why? How Small is an Atom?

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 Groups: Vertical Columns 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