The Periodic Table of the Elements All matter is composed of elements. All of the elements are composed of atoms. An atom is the smallest part of an element which still retains the properties of that element. All of the elements are listed on the Periodic Table by their Chemical Symbol • The chemical symbol for every element is either one capital letter or one capital letter plus a small letter For example: C = carbon Ca = calcium Cl = chlorine Cr = chromium Chemical Symbols Chemical Symbols • represent name of element • consist of one to two letters and start with capital 1-Letter Symbols 2-Letter Symbols C carbon Co cobalt N nitrogen Ca calcium F fluorine Al aluminum O oxygen Mg magnesium 3 Refer to Table 4.2 on Page 97 for list of the more common elements and their symbols. All of the elements on the Periodic Table are arranged in vertical columns called “Groups”, and in horizontal rows called “Periods”. All of the groups have numbers and they are either “A” groups or “B” groups running from left to right on the Periodic Table Periodic Table of the Elements Group** Period 1 18 IA VIIIA 1A 8A 1 2 13 14 15 16 17 2 1 H IIA IIIA IVA VA VIA VIIA He 1.008 2A 3A 4A 5A 6A 7A 4.003 3 4 5 6 7 8 9 10 2 Li Be B C N O F Ne 6.941 9.012 10.81 12.01 14.01 16.00 19.00 20.18 11 12 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 3 Na Mg IIIB IVB VB VIB VIIB ------- VIII --- IB IIB Al Si P S Cl Ar 22.99 24.31 3B 4B 5B 6B 7B ---- 1B 2B 26.98 28.09 30.97 32.07 35.45 39.95 ------- 8 ------- 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 4 K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr 39.10 40.08 44.96 47.88 50.94 52.00 54.94 55.85 58.47 58.69 63.55 65.39 69.72 72.59 74.92 78.96 79.90 83.80 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 5 Rb Sr Y Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb Te I Xe 85.47 87.62 88.91 91.22 92.91 95.94 (98) 101.1 102.9 106.4 107.9 112.4 114.8 118.7 121.8 127.6 126.9 131.3 55 56 57 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 6 Cs Ba La* Hf Ta W Re Os Ir Pt Au Hg Tl Pb Bi Po At Rn 132.9 137.3 138.9 178.5 180.9 183.9 186.2 190.2 190.2 195.1 197.0 200.5 204.4 207.2 209.0 (210) (210) (222) 87 88 89 104 105 106 107 108 109 110 111 112 114 116 118 7 Fr Ra Ac~ Rf Db Sg Bh Hs Mt --- --- --- --- --- --- (223) (226) (227) (257) (260) (263) (262) (265) (266) () () () () () () 58 59 60 61 62 63 64 65 66 67 68 69 70 71 Lanthanide Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu Series* 140.1 140.9 144.2 (147) 150.4 152.0 157.3 158.9 162.5 164.9 167.3 168.9 173.0 175.0 90 91 92 93 94 95 96 97 98 99 100 101 102 103 Actinide Series~ Th Pa U Np Pu Am Cm Bk Cf Es Fm Md No Lr 232.0 (231) (238) (237) (242) (243) (247) (247) (249) (254) (253) (256) (254) (257) Learning Check Give the names of the elements with the following symbols: A. P B. Al C. Mn D. H E. K 7 Solution Give the names of the elements with the following symbols: A. P = phosphorus B. Al = aluminum C. Mn = manganese D. H = hydrogen E. K = potassium 8 Groups Columns of elements define element groups. Elements within a group share several common properties. Periods Rows of elements are called periods. The period numbers increase as you go from top to bottom on the periodic table. The number of elements in a period increases as you move down the periodic table. Using grid coordinates (like a checkerboard) each element can be located on the Periodic Table. Refer to Figure #4.2 on Page 100 Solution Identify the element described by the following: 1. Group 7A, Period 4 bromine 2. Group 2A, Period 3 magnesium 3. Group 5A, Period 2 nitrogen 11 Learn the names of the groups: Ia = alkali metals IIa = alkaline earth metals All “B” groups = Transition metals VIIA = halogens VIIIA = noble (inert) gases Classification of Groups Page 101 13 Refer to Page 102 Identify each of the following elements as metal, nonmetal, or metalloid. A. sodium metal B. chlorine nonmetal C. silicon metalloid D. iron metal E. carbon nonmetal 14 STRUCTURE OF THE ATOM: Particles that are smaller than the atom are called subatomic particles. • The three main subatomic particles that form an atom are protons, neutrons, and electrons. The center of the atom is called the nucleus. Protons and neutrons make up the nucleus of an atom. The atomicAtomic number Number • is specific for each element. • is the same for all atoms of an element. • is equal to the number of protons in an atom. • appears above the symbol of an element. Atomic Number 11 Symbol Na 16 14 ----------Atomic number Si 28.09 -------- Mass number An atom is the smallest part of an element which still retains the properties of that element. An isotope is another form of an element having a different number of neutrons. An element's or isotope's atomic number tells how many protons are in its atoms. An element's or isotope's mass number tells how many protons and neutrons in its atoms. Subatomic Electrical Particle Mass Charge P 1 +1 N 1 0 e 0 -1 Subatomic Particles in the Atom See Page 108 4.5 21 Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. • Protons have a positive electrical charge, so they are often represented with the mark of a "+" sign. • Neutrons have no electrical charge Learning Check Identify each statement as describing a 1) proton, 2) neutron, or 3) electron. A. found outside the nucleus B. has a positive charge C. is neutral D. found in the nucleus 23 Atomic Number The atomic number • is specific for each element • is the same for all atoms of an element • is equal to the number of protons in an atom • appears above the symbol of an element in the Periodic Table Atomic Number 11 Symbol Na 24 Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Every element, standing alone, in its neutral or uncombined state, MUST have an overall electrical charge of ZERO. • That means that the number of electrons (negatives) must equal the number of protons (positives). Atoms Are Neutral For neutral atoms, the net charge is zero. number of protons = number of electrons Aluminum has 13 protons and 13 electrons. The net (overall) charge is zero. 13 protons (13+) + 13 electrons (13–) = 0 26 Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Composition of Some Atoms of Different Elements See Page 110 Table 4.6 27 Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Learning Check Use the periodic table to fill in the atomic number, number of protons, and number of electrons for each of the following elements: Element Atomic Protons Electrons Number N Zn S 28 Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Solution Use the periodic table to fill in the atomic number, number of protons, and number of electrons for each of the following elements: Element Atomic Protons Electrons Number N 7 7 7 Zn 30 30 30 S 16 16 16 29 Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. • Elements: Each element has a fixed number of positively charged protons in its nucleus and an equal number of electrons orbiting the nucleus. For example, hydrogen (H) has one proton and one electron, but lead (Pb) has 82 protons and 82 electrons. There are about 115 known elements of which 82 are naturally abundant. Study Tips: Protons and Neutrons Number of protons = atomic number Number of protons + neutrons = mass number Number of neutrons = mass number – atomic number Note: Mass number is given for specific isotopes only. 31 Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Learning Check An atom of lead (Pb) has a mass number of 207. A. How many protons are in the nucleus? B. How many neutrons are in the nucleus? C. How many electrons are in the atom? 32 Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Solution An atom of lead (Pb) has a mass number of 207.