Chapter 6 The Periodic Table and Periodic Law Historical Timeline Development of the Periodic Table Thursday and Friday 6.1 Development of the Periodic Table • Late 1790s • Antoine Lavoisier • compiled a list of all elements known at the time23 elements • 1800s- invention of electricity, development of spectrometer, and industrial revolution led to explosion in the number of known elements • By 1870 there were 70 known elements • 1864 • John Newlands • created law of octaves, which means that properties repeat every 8th element • Law doesn’t work for all elements • 1869 • Meyer and Mendeleev demonstrated a connection between atomic mass and elemental properties • 1869 • Mendeleev organized 1st periodic table by atomic mass and left blank spaces where undiscovered elements should go- not completely correct • 1913 • Moseley arranged elements according to atomic number • Periodic Law – the periodic repetition of chemical and physical properties of elements when they are arranged by increasing atomic number The Modern Periodic Table • Consists of boxes containing element name, symbol, atomic number, and atomic mass Friday • We will finish the historical timeline of the periodic table • We will color the two main sections of the periodic table: • Representative elements • Transition elements • We will color in the metals and the nonmetals and the metalloids • Representative Elements- main group of periodic table (1,2, and 13-18), s and p block; represent a wide range of chemical and physical properties • Transition Elements- groups 3-12 Classifying the Elements • Metals- elements that are generally shiny, solids at room temperature, good conductors of heat and electricity, malleable (able to be pounded into thin sheets), and ductile (drawn into wires) • Nonmetals- generally gases or brittle, dull-looking solids; poor conductors of electricity • Metalloids- elements with physical and chemical properties of both metals and nonmetals Monday • We will make a foldable over the different types of groups in the periodic table The Families of the modern Periodic Table • Alkali Metals- Group 1A (1) • Alkaline Earth Metals- Group 2A (2) • Both groups are chemically reactive • Transition Metals- Group B elements (d block) • Inner Transition Metals- (f block) • Halogens- Group 7A (17); highly reactive • Noble Gases- Group 8A (18); extremely unreactive Classifying the Elements • S-block elements –groups 1A and 2A –Holds a maximum of two electrons • P-block elements group 3A through 8A, or 13-18 Holds a maximum of 6 electrons • d-block elements – contains transition metals – largest block – holds maximum of 10 electrons • f-block elements – contains inner transition metals – lanthanide and actinide series – holds maximum of 14 electrons • Tuesday - Exploration Activity Lab over the periodic trends of the Periodic Table Wednesday • We will do trends on the periodic table • Compare our notes to he lab from Tuesday 6.3 Periodic Trends • Atomic Radius generally increases from right to left and increases from top to bottom of the periodic table • Adaptive Curriculum Clip Atomic Size • Ionic Radius- positive ions decrease from left to right until group 3A (13), then negative ions decrease until 8A (18); generally increases from top to bottom • Ion- atom or bonded group of atoms that has a positive or negative charge Cation –positively charged ion (lost electron) –Will decrease radius because of loss of outer energy level –Are in groups 1-13 Anions –negatively charged ion (gained electron) –will increase radius because protons “pulling in” are the same and with extra electrons they repel each other and spread out –groups 14-18 Atomic and Ionic radius follow the same trend!! Ionization Energy • energy required to remove an electron from a gaseous atom • generally decreases from right to left and decreases from top to bottom Electronegativity • indicates the relative ability of its atoms to attract electrons in a chemical bond • decreases from right to left and decreases from top to bottom Follows the same trend as electronegativity!! Thursday • We will finish our lab • We will finish our review and check it in class Friday • We will test on Friday