The Periodic Table!!!!

3.1 The Periodic Table History Organization Electron arrangement & valence energy level

Dmitri Mendeleev ; sequenced known elements in order of increasing atomic mass Elements with similar properties in same column. Called Periodic Table because it highlighted the repeated (periodic) patterns of properties.

Periodic Law Chemical & physical properties of the elements repeat in a regular, periodic pattern when arranged by atomic number This is the basis for the modern periodic table – arranged by atomic number.

The Modern Periodic Table Using the information in your data booklet, complete the periodic table worksheet. Be sure to include a legend on your worksheet.

Alkali metals (not H) Alkaline earth metals Transition metals Halogens Noble gases Inner transition G G G G G G GGG G G G L L VIIAVIAVAIVAIIIAIIA VIIAIA Metalloids For more lessons, visit

Group Names: –Two systems: Old & New Old: Roman numerals with either A or B New: Integers 1-18 from left to right Group VA = Group 15 Alkali Metals: –Group 1 –Soft, light, reactive metals Alkaline Earth Metals: –Group 2 –Harder, denser, and stronger than alkali metals

Transition Metals: –Group 3-12 –Form positive ions, reactive, make coloured compounds Metalloids: –On staircase between metals and non-metals –Exhibits properties of both

Halogens: –Group 17; Reactive non-metals –Electron deficient and readily share electrons with other elements Noble Gases: –Group 18 –Do not react chemically with other materials and cannot be absorbed –Valence shell full

The Periodic Table & Electrons Periodic trends are linked to the way electrons fill energy levels. Remember that for each proton there is one electron in an atom, therefore as the atomic number increases, so does the number of electrons. To understand trends, we use the Bohr- Rutherford Model of the atom.

The Bohr-Rutherford Model Electrons in energy levels 2 in first level 8 in other levels What element is this? Sodium, Na

Group Related Pattern: –All the elements in a group have the same number of valence electrons. –The old number system – The roman numeral is the same as the number of valence electrons. –The new system – The last digit of the number is the number of valence electrons. Period-Related Pattern  Period Number = Number of Energy Levels

3.2 Physical Properties Ionization energy Electronegativity Atomic Radii Ionic Radii Across period 3 & down group 1 & 17

More Trends – Worksheet Ionization Energy: The energy required to remove one valence electron from an atom. Electronegativity: How strongly an atom attracts the electrons in a covalent bond Atomic Radius:The distance from the nucleus to the valence electron shell of an atom Ionic Radius: The distance from the nucleus to the valence electron shell of an ion

Ionization energy vs. atomic number

Ionization Energy Trend

Electronegativity Trend

Atomic radius vs. atomic number

Atomic Radius & Ionic Radius ntialchemistry/flash/atomic4.swf

Ionic Radius Trend

3.3 Chemical Properties Group Properties: –Alkali metals with water –Alkali metals with halogens –Halogens with water –Halogens with halide ions Oxides of period 3 properties –Ionic vs. covalent bonding nature –Basic vs. acidic nature –Industrial processes

Alkali metals with H 2 O M + H 2 O  MOH + H 2 Trend:Very reactive; increasing down group Observations: –Highly exothermic – heat & light –Fizzing of hydrogen gas formed –VideoVideo

Alkali Metals with Halogens M + X 2  MX React in 1:1 ratio

Halogens with H 2 O Reactivity decreases down group because electronegativity and oxidizing power decreases down group; electrons farther from nucleus and are shielded Halogens General VideoVideo

Halogen and halide ions Higher Halogen displaces lower halogen from salt; never other way around! Cl 2 + I-  Cl- + I 2 Cl 2 + Br-  Cl- + Br 2 Br 2 + I-  Br- + I 2 Br 2 + Cl-  No rxn I 2 + Cl-  No rxn I 2 + Br-  No rxn

Halogen and metal Make salts with halide ion Salts are usually white in colour and soluble in water creating colourless solutions Common insoluble halides: silver and lead

Things to Know: Ionic compound– attraction of ions creates bond Covalent compound – shared electrons create bond Polar Covalent – a covalent bond where electrons are not shared equally creating positive and negative “ends” on the bond Acidic – having a pH of less than 7; H+ Basic – having a pH of more than 7; OH

Oxides: Compounds containing at least one oxygen atom Bonded with metal: ionic compound & basic Bonded with non-metal: polar covalent compound; polarity decreasing across period & acidic (increasing across period) **aluminum oxide is amphoteric – reacts with acid and base**

Oxide + H 2 O Reactions Na 2 O (s) + H 2 O (l)  2Na + (aq) + 2OH - (aq) MgO + H 2 O → Mg(OH) 2 P 4 O 10(s) + 6H 2 O (l)  4H + (aq) + 4H 2 PO 4- (aq) SO 3(s) + H 2 O  H + (aq) + HSO 4- (aq) Another MgO rxn: MgO (s) + 2HCl (aq)  Mg 2+ (aq) + 2Cl - (aq)