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1. List the properties of: a. metals Conductor of heat and electricity. Malleable, which means that they can be hammered into very thin sheets without breaking. Ductile, which means that they can be drawn into wires. Fresh surface. Solids at room temperature. b. nonmetals Poor conductor of heat and electricity. Brittle— that they will shatter if struck with a hammer. Solids are not lustrous. Can be solid, liquid, or gas at room temperature depending upon the elements c. metalloids or semimetals Intermediate between metals and nonmetals. 2. Who is Dmitri Mendeleev, and what was his contribution to chemistry? Russian chemist and teacher, published a periodic table of the elements. His organization of elements was based on atomic mass. Mendeleev’s periodic table made it possible to predict properties of elements that had not yet been discovered. 3. How is the modern periodic table different from the first periodic table? Mendeleev’s periodic table orders the elements based on their atomic mass whereas Modern periodic table orders the elements based on their atomic number. Mendeleev’s periodic table has 8 vertical columns calaed groups and 12 horizontal rows called periodic. Modern periodic has 18 columns called groups and 7 rows called periods. Mendeleev’s periodic table has elements with dissimilar properties in the same groups sometimes. Modern periodic table elements have similar properties repeated at regular intervals. 4. What is the modern periodic law? The periodic law states “when elements are arranged in order of increasing atomic number, there is a periodic repetition of their chemical and physical properties” 5. Organization of the periodic table. Indicate where the following are located on the periodic table. a. periods Horizontal called periods. b. groups chemical properties appear at regular intervals, within the vertical columns called groups. c. Alkali metals Group 1 d. Alkaline Earth Metals Group 2 e. Halogens Group 17 f. Noble Gases Group 7 g. Representative or Main Grou h. Transition Metals Group IIIA-IIB (new group 3-12) i. Inner Transition Metals k. Lanthanides l. Actinides 89-103 m. metals n. nonmetals o. metalloids 6. Indicate which elements on the periodic table are: a. gases at room temperature. Fluorine, oxygen, chlorine, nitrogen and hydrogen, Radon, helium, xenon, neon, krypton and argon b. liquids at room temperature. Group one elements, Bromine and Mercury 7. Trends in the periodic table. a. How does the size of the atom vary as you move left to right across the periodic table? Why? Atomic size decrease as you move left to right across a period. because there are more protons and electrons, which create greater attraction. b. How does the size of the atom vary as you move down the periodic table? Why? The size increase, because increasing number of electron shells. where the inner shells reduce the attractive forces of the nucleus and repel the electrons in the outer shell, decrease. Additional electrons in elements with higher atomic numbers are filling orbitals that have a larger average radius. The size of atoms in determine by the size of the electron distribution of the valence orbitals. c. What is ionization energy? Is the energy required to remove an electron form a specific atom. It is measured in kj/mol. d. How does the ionization energy vary as you move left to right across the periodic table? Why? The inoization energy for an atom increases, because the more protons in the nucleaus, the stronger the attraction of the nucleus to electrons. e. How does the ionization energy vary as you move down the periodic table? Why? Ionization energy decreases as we go down a group, because electron removed is farther from the nucleus as the number of protons increases. Being farther away from the positive attraction makes it easier for that electron to be pulled off. f. What is electron affinity? Electron affinity is a measure of the energy released when an extra electron is added to an atom. Electron affinities are measured in the gaseous state. g. How does electron affinity vary as you move left to right across the periodic table? Why? Electron affinities increase (more negative). h. How does electron affinity vary as you move down the periodic table? Why? Electron affinity decrease i. What is electronegativity? Electronegativity is a measure of the ability of an atom to attract the electrons when the atom is part of a compound. j. How does electronegativity vary as you move left to right across the periodic table? Increase k. How does electronegativity vary as you move down the periodic table? Decrease