Presentation on theme: "Chapter 6 The Periodic Table"— Presentation transcript:
1 Chapter 6 The Periodic Table Ms. WangLawndale High School
2 Section 6.1 - Organizing the Elements By the 1700’s, only about 13 elements had been identifiesChemists used the properties of elements to sort them into groupsIn 1829, J.W. Dobereiner published a classification system with elements grouped into set of three based upon similar chemical properties
3 Mendeleev’s Periodic Table From 1829 to 1869, many different systems were proposed, but none gained wide acceptanceIn 1869, Dmitri Mendeleev arranged the elements in his periodic table in order of increasing atomic mass, based upon repeating properties
4 The Periodic LawIn the modern periodic table, elements are arranged in order of increasing atomic numberPeriodic Law – when elements are arranged in order of increasing atomic number, there is a periodic repetition of their physical and chemical properties
5 Metals, Metalloids and Nonmetals (Red ladder on the periodic table) Elements can be grouped into three broad classes based on their general propertiesMetalsNonmetalsMetalloids
6 Metals: elements that are generally solid at room temperature, have a grayish color and shiny surface, and conduct heat and electricityNonmetals: elements that have varying properties but are generally poor conductors of heat and electricityMetalloids: elements with some properties of metals and and nonmetals
7 Section 6.2 - Classifying the Elements (Page 162-163) The periodic table displays the symbols and names of the elements, along with information about the structure of their atomsElement symbols that are printed in black are solid at R.T., blue are liquid at R.T., and red are gasses at R.T.Some elements are printed in green, which means that they are not found in nature
8 The 7 Groups of the Periodic Table Alkali Metals (Group 1A)Alkaline Earth Metals (Group 2A)Chalcogens (Group 6A)Halogens (Group 7A)Noble Gases (Group 8A)Transition Metals (Group B)Inner Transition Metals (Lanthanides and Actinides)
9 Electron Configurations in Groups Elements can be sorted into noble gases, representative elements, transition metals, or inner transition meals based on their electron configurationNoble Gases always have their s and p sublevels completely filled with electrons, which makes them relatively inactive
10 Representative Elements Representative Elements are Groups 1A through 7A because they display a wide range of physical and chemical propertiesFor any representative element, its group number always equals the number of electrons in the highest occupied energy level (Valence Shell)
11 Transition MetalsTransition Metals are characterized by the presence of electrons in the d orbitalInner Transition Metals are characterized by the presence of electrons in the f orbital
12 Section 6.3 – Periodic Trends Properties of elements are related to the location of elements in the periodic tableFour periodic trends:Atomic RadiusIonization EnergyElectron AffinityElectronegativity
13 1. Atomic RadiusOne-half of the distance from center to center of two atoms of the same elementAtomic Radius
14 1. Atomic RadiusWhat do you notice about the atomic radii of the elements on the periodic table?
15 Atomic Radius Practice Which element has a greater atomic radius?F or CsGa or KKr or RbPut these elements in order of increasing atomic radiusBa, Si, Fr, W, O, Ag
16 IonsRemember that atoms that are electrically neutral have equal number of protons and electronsSome compounds are composed of particles called ions.Ions are atoms that have a positive or negative charge.
17 IonsPositive and negative ions form when electrons are transferred between atomsCation – an ion with a positive chargeAnion – an ion with a negative charge
18 2. Ionization EnergyThe energy required to remove an electron from an atom-+Lithium IonLithium atom
19 2. Ionization EnergyElements with low ionization energy are good conductors of electricity
20 2. Ionization EnergyWhat trend do you notice about the ionization energy of the elements on the periodic table?
21 Ionization Energy Practice Which of these elements has a greater ionization energy?Ar or KrAl or NaS or RbPut these elements in order of increasing ionization energySi, Cs, He, Ca, P, O
22 Ionic SizeCations are always smaller than the atoms from which they formAnions are always larger than the atoms from which they formWHY? (Hint: think about the electron cloud of an atom)Which is larger? Na or Na+, Al or Al3+, I or I-, S or S2-
23 3. Electron AffinityWhat trend do you notice about the electron affinity of the elements on the periodic table?
24 4. ElectronegativityThe tendency of an atom to attract electrons to itself when in a compound
25 4. ElectronegativityWhat trend do you notice about the electronegativity of the elements on the periodic table?
26 Electronegativity Practice Which element has greater electronegativity?Na or FCa or CAl or MgPut these elements in order of increasing electronegativitySr, Al, Ca, K, Cl, F