1C – Students know how to use the Students know how to use the periodic table to identify alkali metals, alkaline earth metals and transition metals trends in transition metals, trends in ionization energy, electronegativity, and the relative sizes of ions and d h l f d atoms. Alkali Metals Alkali Metals • Alkali Metals – Group 1 elements, except for Hydrogen ‐ Li, Na, K, Rb, Cs, Fr 2. Alkaline Earth Metals – Group 2 elements. ‐ Be, Mg, Ca, Sr, Ba, Ra B M C S B R 3. Transition Metals – Groups 3 through 12, include the most common metals like iron, include the most common metals like iron, copper, and gold. 4. Noble Gases – Group 18 elements. ‐ He, Ne, Ar, Kr, Xe, Rn 5. Ionization Energy – The energy it takes to remove an electron from an atom. l f 6. Electronegativity – The ability of an atom of an element to attract electrons to itself in a an element to attract electrons to itself in a chemical bond Alkali Metals Alkali Metals ALKALI METALS The first family in the table of elements. Does NOT incl de H drogen (H) Does NOT include Hydrogen (H) Soft and white, and light in weight Extremely reactive because of their desire to bond with other elements. • Explosive when exposed to water! • • • • Alkaline Earth Metals Alkaline Earth Metals • • • • • The second family in the table of elements. Second most reactive family of Second most reactive family of elements. When they are mixed with liquids they form ‘alkaline’ form alkaline solutions. solutions Calcium (Ca) and Magnesium (Mg) are important for plants and animals. U d i thi Used in things like batteries, fireworks, lik b tt i fi k and flashbulbs. ALKALINE EARTH METALS 1C ‐ Classwork/Homework / 1. What is one fact each about the following alkali metals? (pg. 181 182) 181‐182) a. b. c. 2. 3. Why are alkali metals stored in oil? (pg. 181) What is one fact each about the following alkaline earth metals? (pg. 183‐184) a. b. c. 4 4. Lithium Sodium Potassium Beryllium Calcium Magnesium Name three factors that make magnesium a good choice for N h f h k i d h i f alloys. Transition Metals Transition Metals TRANSITION METALS TRANSITION METALS • Element groups 3 – 12 and the elements in the and the elements in the two periods below are all transition metals. • Some of the most Some of the most common metals, like copper, gold, and silver, are transition metals. are transition metals. • They act like all other metals, but the electrons they use to combine with they use to combine with other elements are in different shells/orbitals. Noble Gases Noble Gases • The eighteenth family in the table of elements. • Do not react with other elements. • Neon (Ne) is used in neon signs, Argon (Ar) is used in light bulbs Helium (He) is light bulbs, Helium (He) is used in balloons, Xenon (Xe) is used in the headlights of cars. NOBLE GASES Classwork/Homework / 1. What are the five (5) transition metals that are found in nature uncombined with other elements? nature uncombined with other elements? 2. What transition metals are found in South Africa? Mexico? (pg. 200) 3 What is one fact each about the following noble gases? 3. Wh t i f t h b t th f ll i bl ? (pg. 196) a. b b. c. Helium N Neon Argon 4. Why where noble gases the last naturally occurring elements to be discovered? l b di d? Electronegativity • Measure Measure of the ability of an atom to of the ability of an atom to attract shared electrons • Larger electronegativity means atom attracts shared electrons more strongly attracts shared electrons more strongly Electronegativity (cont.) Trend in Ionization Energy • Minimum Minimum energy needed to remove a valence energy needed to remove a valence electron from an atom • The lower the ionization energy, the easier it is to remove the electron. – Metals have low ionization energies Trend in Atomic Size Atomic Radius Within A Group Atomic radius increases going down each group of representative elements. Atomic Radius Across a Period Going across a period left to right, • an increase in number of protons increases attraction for valence electrons. • atomic radius decreases. Ionization Energy, Electronegativity, and Atomic Size d • Ionization energy is the energy it takes Ionization energy is the energy it takes to remove an electron from an atom. The closer the electrons are to the nucleus the harder it is to pull them away from the atom • • IONIZATION ENERGY Electronegativity measures the ability of an atom of an element to attract electrons toward itself in a bond electrons toward itself in a bond. ELECTRONEGATIVITY • The more protons an atom has in its nucleus the better it can attract electrons. • Atomic and Ionic sizes are a measure of the distance between the electrons and the nucleus. • If there are more shells, or orbitals, in an , , atom, then the electrons will be further away from the nucleus. ATOMIC SIZE 1C ‐ Classwork/Homework / 1. For each of the following pairs of elements, decide which has the largest ionization decide which has the largest ionization energy, electronegativity, and atomic size: a. F and I F dI b. Na and Mg c. Cs and Ba C dB d. C and Si 2 Explain 2. Explain why ionization energy decreases as why ionization energy decreases as you go down a group. 3. Explain why atomic radii decreases as you l i h i dii d move left‐to‐right across a period.