Periodic Table-Chapter 6 Resources and Activities Good video song and animation Periodic table: http://www.youtube.com/watch?v=zGM- wSKFBpo&feature=related TB and Chapter 6 reading and study guide Dynamic periodic Table: http://www.ptable.com/ Regents reference tables- S and Periodic Table and table S What do the elements look like? http://www.periodictable.com/ Animations – metal character, ionization energy and metal reactivity Reaction of Alkali Metals with Water Brainiac Videos on You Tube: http://www.youtube.com/watch?v=m55kgyAp YrY What can you discover and conclude about periodic trends ? Periodic Table Lab Activities (1) Color Coded Periodic Table (2) POGIL on Periodicity of Elements (3) Graphing of Periodic Properties versus Atomic Number – “Periodic Trends-Student Sheet” (4) “Overview of Periodic Properties”

Dmitri Mendeleev (1869) In 1869 Mendeleev and Lothar Meyer (Germany) published nearly identical classification schemes for elements known to date. The periodic table is base on the similarity of properties and reactivities exhibited by certain elements. Later, Henri Moseley ( England,1887-1915) established that each elements has a unique atomic number, which is how the current periodic table is organized. http://www.chem.msu.su/eng/misc/mendeleev/welcome.html

Periodic Table- Historical Development Dmitri Mendeleev’s Periodic Table (late 1800’s) Elements were arranged according to increasing atomic mass. Other chemists? Lothar Meyer He predicted the physical and chemical properties of missing elements by averaging the properties of the known elements. Henry Moseley – in 1913 he determined the nuclear charge (atomic number of the element). He arranged the periodic table by order of increasing atomic number. Periodic law states that when the elements are arranged by atomic number, their physical and chemical properties vary periodically.

Modern Periodic Table Modern periodic Table is organized based on atomic number of the elements and their chemical properties Vertical columns – groups or families similar chemical and physical properties Same number of valence electrons Valence Electrons are the electrons in the highest occupied energy level of an element’s atom; outer-most electrons Valence electrons determine the chemical properties of the element. 7 horizontal rows – periods – contain elements with valence electrons in the same principle energy level Properties within a period change

Characteristics of Metals, Nonmetals, and Metalloids Nonmetals are found in upper right hand corner of the periodic table. They can be gases or molecular or network solids at room temperature (bromine is an exception and is a liquid at room temperature). They are poor conductors, dull, brittle; only carbon (graphite) conducts. Nonmetals have high ionization energies and high electronegativities. Nonmetals tend to gain electrons to become negative ions with larger radii than their atoms. Fluorine is a highly reactive nonmetal. Metalloids– have properties that are similar to metals and nonmetals; found along the diagonal (ex:Si,Ge) Noble Gases or Inert Gases- Group 18, are chemically inert (with some rare exception). Metals are good conductors of heat and electricity, are malleable, ductile, and make up most of the periodic table. They also have luster. Most metals are solids are room temp (except Hg which is a liquid). Metals have low ionization energies and electronegativities. Metals tend to lose electrons to form positive ions (cations) with smaller radii. Metallic character increases as you go down (descend) the group 1 alkali metals and the group 2 alkaline earth metals. Francium and Cesium are highly reactive metals. Reaction of Alkali Metals with Water Brainiac Videos on You Tube: http://www.youtube.com/watch?v=m 55kgyApYrY

Reading the Periodic Table: Classification Nonmetals, Metals, Metalloids, Noble gases

Periodic Table trends and Metallic character Elements with low ionization energies tend to be metals. Those with high ionization energies tend to be nonmetals. This can vary within a group as well as within a period.

Periodic Table Group 1 – Alkali Metals, most reactive metals (one valence electron). Groups with either nearly empty or nearly full valence shells tend to be particularly reactive. Group 2 - Alkaline Earth Metals, second most reactive group of metals (2 valence electrons) Note that Hydrogen is a Non metal and is NOT an alkali metal. Group 17 – Halogens, F, Cl, Br, I, most reactive nonmetals (recall - groups with either nearly empty or nearly full valence shells tend to be particularly reactive). Group 17 : Halogens (have 7 valence electrons), are the most reactive nonmetals; undergo chemical reactions to gain 1 e- to get to a Noble gas configuration. Video of reaction of chlorine gas with sodium metal http://jchemed.chem.wisc.edu/jcesoft/cca/cca0/movies/nacl1.html Group 18 – Noble Gases, Inert, Ne, Ar, Kr, Xe, He,

Periodic Table s block : Groups 1,2 and He p block : Groups 13-18 Main Group Elements d block: Transition Elements – outermost electrons are in the d orbitals. (d block metals; the d orbitals have a numeric label that is 1 less than the period number . Example: Electron configuration of elements Dynamic periodic Table: http://www.ptable.com/

Ionization Energy of Elements The energy needed to remove an electron from a gaseous atom is called the Ionization Energy. Ex. K  K+ + e- Group Trends – Ionization Energy decreases as you move down a group. Size of the atom increases as you move down a group and the valence electrons are further from the nucleus, and therefore more weakly held (by their attraction to the nucleus) and are easier to remove

Periodic Table Electronegativity – is the tendency for atoms of the element to attract electrons when they are chemically combined with another element. F has the highest electronegativity, Fr has the lowest electronegativity and cesium has the next lowest electronegativity. Periodic Trends – Electronegativity increases from left to right. Nonmetals attract electrons Group Trends- Electronegativity increases from bottom to top. F has the highest electronegativity of the halogens.

Periodic Table Periodic trends in ionization energy- ionization increases as you move from left to right across the period. As you move towards the right, there is a greater attraction of the nucleus for its outer electrons. Electrons are less likely to be lost. Electrons in the outermost shell available to be lost, gained or shared in the formation of chemical compounds are called Valence electrons. K  K+ + e- Cations are smaller than their neutral atoms, anions are larger than their neutral atoms.

P. Table - Atomic Size/Atomic Radius Periodic Trends in Atomic Size – X-Ray diffraction is used to determine size of solid atoms. Atomic Radius – half the distance between the nuclei of two like atoms. Group Trends- Atomic size increases as you move down a group on the periodic table. You add more protons, neutrons, electrons, and energy levels overall. Atomic Size decreases as you move from left to right across a period. As more electrons are added to the same energy level, they are pulled in tighter to the nucleus (with increasing nuclear charge).

Periodic Table (what about transition elements?) Properties of the d-block elements vary with less regularity than the main-group elements. Their atomic radii generally decrease across a period. Ionization Energy and electronegativity also shows the same trends for the d-block. D-block elements remove electrons from the outer s shell before d electrons are removed from the outer shell.

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Periodic Table-Chapter 6 Resources and Activities Good video song and animation Periodic table: http://www.youtube.com/watch?v=zGM- wSKFBpo&feature=related TB and Chapter 6 reading and study guide WB – Periodic Table Unit for content and practice problems Dynamic periodic Table: http://www.ptable.com/ Regents reference tables- S and Periodic Table and table S What do the elements look like? http://www.periodictable.com/ Animations – metal character, ionization energy and metal reactivity Reaction of Alkali Metals with Water Brainiac Videos on You Tube: http://www.youtube.com/watch?v=m55 kgyApYrY What can you discover and conclude about periodic trends ? Periodic Table Lab Activities (1) Color Coded Periodic Table (2) POGIL on Periodicity of Elements (3) Graphing of Periodic Properties versus Atomic Number – “Periodic Trends-Student Sheet” (4) “Overview of Periodic Properties”