Transcript power point
Assignments I have found related jognog quizzes you can do for extra point’s pts. to replace the missing naming HW. There is also a balancing equations page to use as make up points on those assignments. Jognog Code JSX4R7F (All scores have to be greater than 85% to earn credits.) In addition I have assigned you three periodic table jognog quizzes to go along with the power point I have assigned you for the break. Please have these completed by the time we are back at school. Introduction to the Periodic Table Atomic Number ● Symbol ● Atomic Weight Element ● Compound ● Mixture Periodicity Objectives Be able to: Explain how the early versions of the periodic table was organized by the following people – Mendeleev – Mosley State the periodic law Define Periods and groups/families of the table Identify the following groupings in the table and their tables – Metals, non-metals, metalloids, – Alkali metals, Alkali earth metals, transition metals, Halogens, noble gases, Rare earth elements(Lanthanide and actinide series) Describe the following trends in the periodic table. (Trends through the period and the family.) – – – – Atomic Radii Density Ionization energy Electron affinity/ electronegativity List or identify the properties of the metals and non-metals. Homework Take notes on the previously listed objectives. You can also color in a periodic table to identify the areas required. Use the periodic tables in your notes or download one and use your smart phones to label it. Be resourceful. Also, I have assigned you two jognog quizzes to complete. You will only receive credit if you earn 85% or above. Jognog code JSX4R7F I am Dmitri Mendeleev! I made the PERIODIC TABLE ! Mendeleev’s Periodic Table “I began to look about and write down the elements with their atomic weights and typical properties, analogous elements and like atomic weights on separate cards, and this soon convinced me that the properties of elements are in periodic dependence upon their atomic weights.” --Mendeleev, Principles of Chemistry, 1905, Vol. II What is the PERIODIC TABLE? o Shows all known elements in the universe. o Organizes the elements by chemical properties. How do you read the PERIODIC TABLE? What is the ATOMIC NUMBER? o o The number of protons found in the nucleus of an atom Or The number of electrons surrounding the nucleus of an atom. What is the SYMBOL? o An abbreviation of the element name. What is the ATOMIC WEIGHT? o The number of protons and neutrons in the nucleus of an atom. How do I find the number of protons, electrons, and neutrons in an element using the periodic table? o # of PROTONS = ATOMIC NUMBER o # of ELECTRONS = ATOMIC NUMBER o # of NEUTRONS = ATOMIC _ ATOMIC WEIGHT NUMBER Now you are almost as smart as I am! But not as handsome! Man, I look GOOD! What is an ELEMENT? o A substance composed of a single kind of atom. o Cannot be broken down into another substance by chemical or physical means. What is a COMPOUND? o A substance in which two or more different elements are CHEMICALLY bonded together. What is a MIXTURE? o Two or more substances that are mixed together but are NOT chemically bonded. You are still not as handsome as the great Mendeleev! I am working this beard! Man, I look GOOD! Henry Moseley (1887-1915) English chemist Worked with Rutherford Proved Mendeleev’s arrangement of the periodic table to be correct – only, the periodic table was arranged according to atomic number, not atomic mass The Periodic Law States that when elements are arranged in order of increasing atomic number, their physical and chemical properties show a periodic pattern How do we read the table? The modern periodic table has 118 squares, which represent a unique element. The distinctive shape of the periodic table comes in part from the periodic law. Elements in the same column have similar properties. These columns are referred to as groups or families of elements. The horizontal rows of the periodic table are called periods. The elements in the periodic table are also grouped as metals, nonmetals, and semimetals. Metals make up most of the periodic table and are located in the center and at the left of the table. With the exception of hydrogen, nonmetals are on the right side, and semimetals are located between the metals and nonmetals. metals, nonmetals and metalloids. METALS METALLOIDS NONMETALS Nonmetals Good conductors of heat and electricity Malleable Ductile Luster Typically solids at room temperature Nonmetals Solids, liquids and gases at room temperature Solids are brittle and dull Poor conductors of heat and electricity Metalloids Have properties of both metals and nonmetals Mostly brittle solids Intermediate conductors of electricityAKA semiconductor ALKALI METALS Extremely reactive Readily react with water and air Silvery in appearance Soft enough to cut with a knife Lower densities than other metals Lower melting points than other metals ALKALINE-EARTH METALS Harder & stronger than alkali metals Higher densities & melting points than alkali metals Less reactive than alkali metals HALOGENS Most reactive nonmetals React readily with most metals to form salts Most electronegative elements NOBLE GASES Least reactive elements because their highest occupied energy levels are completely filled with an octet of electrons (except He, which only requires 2 electrons to be filled). TRANSITION METALS High densities High melting points Good conductors of heat & electricity High luster Less reactive than alkali and alkaline-earth metals INNER TRANSITION (Rare Earth) METALS LANTHANIDES Soft, silvery metals Similar reactivity to alkaline-earth metals ACTINIDES All radioactive The first 4 have been found naturally on Earth PERIODS GROUPS Atomic radius - Decreases across a period. Protons are added to the nucleus moving across a period from left to right. This increases the charge of the nucleus and electrons are pulled closer to the nucleus. Atomic Radii Variations in Ionization Energies Energy vs Atomic Number Ionization Energy - The energy required to take an electron and become ionized. Chemical activity and bonding depends on taking or sharing electrons Getting to big makes it harder to hold onto E-. Being smaller allows you to grab E- from other atoms. Ionization Energy Trends INCREASES INCREASES Electronegativity A measure of the ability of an atom in a chemical compound to attract a bonding pair of electrons NOTE *Electronegativity is a property of atoms in compounds and thus differs from ionization energy and electron affinity, which are properties of isolated atoms* Trends Increase across a period Effective nuclear charge increases Decrease down a group Increase in atomic size and increase in electron shielding decreases the effective nuclear charge Electronegativity depends upon: The number of protons in the nucleus The distance from the nucleus Electron shielding Electronegativity trends INCREASES INCREASES Big Picture Fluorine and Francium are the most reactive elements. How do you asses an atoms reactivity? Reactivity depends on # of Protons, The distance from the nucleus and Electron shielding Moving towards Fluorine on the table, protons increase. This means greater attraction to eand grabbing free or weakly held e-. Moving towards Francium the E- shells increase. Full electron shells means greater electron repulsion and less attractive forces to e- in the outer shell. Electronegativity Trends INCREASES INCREASES