1 2 3 4 5 6 7 Unit C8: The Periodic Table Chemistry A Developing the Periodic Table Mendeleev arranged his periodic table on the basis of the similar properties of elements. He concluded that the properties of elements were a function of atomic mass. Mendeleev originally put the elements in order according to their a) atomic number b) mass number c) atomic mass d) oxidation number Developing the periodic table The modern periodic table has elements ordered according to their atomic number and grouped by the number of valence electrons they have. The modern periodic table has elements placed in order according to their a) atomic number b) mass number c) atomic mass d) oxidation number Groups Columns are called groups. Elements in the same group have similar chemical and physical properties because they have the same number of valence electrons. 1
Elements in the same group all have a) the same atomic number b) identical physical and chemical properties c) the same number of electrons in their outer energy level d) the same number of protons in their nucleus e) similar sizes 8 9 10 11 12 13 Groups Groups are numbered using two different systems; for convenience, we will use the IUPAC system In the IUPAC system, the groups are each identified by a a) number b) Roman numeral c) letter d) both a and c e) both b and c Period Rows are called periods. Elements in the same period have similar sizes because they have valence electrons in the same energy level. Elements in the same period all have a) the same atomic number b) identical physical and chemical properties c) the same number of electrons in their outer energy lever d) the same number of protons in their nucleus e) similar sizes Period Elements in the same period do not share physical and chemical properties 2
Elements that share physical and chemical properties are probably in the same a) period b) group c) range d) domain 14 15 16 17 18 19 Metals and non-metals Elements can be identified as metals, non-metals, and noble gases. The three broad classifications of elements are a) reactive, non-reactive, and inert b) metals, non-metals, and noble gases c) solids, liquids, and gases d) endothermic, exothermic, and isothermic Metals and non-metals There is a zigzag line that runs diagonally from boron to astatine. Elements below and to the left of this line are metals; elements above and to the right of this line are non-metals. Titanium and calcium would be classified as a) metals b) non-metals c) noble gases d) cannot be determined from the information given. Metals Metals are good conductors of heat and electricity, are malleable and ductile, and have luster. In chemical reactions metals tend to lose electrons and become cations. 3
Metals a) are poor conductors of heat b) tend to be brittle c) are often gases at room temperature d) all of these e) none of these 20 21 22 23 24 25 Metals Metal atoms attach to other metal atoms using metallic bonds. The types of bonds that attach one metal atom to other metal atoms are a) ionic bonds b) metallic bonds c) covalent bonds Non-metals Non-metals are poor conductors of heat and electricity. Non-metals look dull and tend to be brittle if they are solids; many non-metals are gases at room temperature. Non-metals a) are poor conductors of heat b) tend to be brittle c) are often gases at room temperature d) all of these e) none of these Non-metals In chemical reactions non-metals tend to gain electrons and become anions, or they share electrons in covalent bonds and form molecules. The types of bonds that attach one non-metal atom to another non-metal atom are 4
non-metal atom are a) ionic bonds b) metallic bonds c) covalent bonds 26 27 28 29 30 31 The types of bonds that attach a non-metal atom to a metal atom are a) ionic bonds b) metallic bonds c) covalent bonds Metalloids Elements that are on the line separating metals from nonmetals are called metalloids. Metalloids share properties of both metals and non-metals. Elements on the line that separate the metals from the nonmetals are a) poor metals b) coinage metals c) metalloids d) lanthanides Metalloids Metalloids can appear to be metallic, such as aluminum, or non-metallic, such as silicon. Aluminum would be an example of a) an alkali metal b) a transition metal c) a metalloid d) a non-metal e) none of these Noble gases Elements in group 18 are called noble gases. 5
Elements in group 18 are called noble gases. Noble gases have their outer energy levels filled and tend not to gain or lose electrons. 32 33 Noble gases Chemically, these elements are non-reactive except in very rare circumstances, and are gases at room temperature. The reason that noble gases do not easily react with other elements is that they a) are all gases b) are very, very small c) have their outer energy levels filled d) all of the above e) none of the above 6