CHAPTER Atoms,Elements, Periodic Table 1
Vocabulary Chemistry Science that describes matter its properties, the changes it undergoes, and the energy changes that accompany those processes Matter Anything that has mass and occupies space.
Elements Elements substances that cannot be decomposed into simpler substances via chemical reactions Elemental symbols found on periodic chart First letter capital, second letter lower case C, Ca, Co CO is not an element. 3
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The Periodic Table: Metals Some properties of metals 1. Form cations by losing electrons (+ charge). Form ionic compounds with nonmetals 3. Typically solids (except mercury) 4. Shiny 5. Conduct Electricity 6. Ductile 7. Malleable 6
The Periodic Table: Metals, Nonmetals, and Metalloids Groups or families Vertical group of elements on periodic table Similar chemical and physical properties 7
The Periodic Table: Metals, Nonmetals, and Metalloids Period Horizontal group of elements on periodic table Transition from metals to nonmetals 8
The Periodic Table: Metals Group IA metals Alkali metals Li, Na, K, Rb, Cs, Fr Group IIA metals Alkaline earth metals Be, Mg, Ca, Sr, Ba, Ra 9
The Periodic Table: Nonmetals Some chemical properties of nonmetals 1. Form anions by gaining electrons (- charge). Form ionic compounds with metals and covalent compounds with other nonmetals 3. Noble gasses have full shells 4. Do not conduct electricity 5. Poor conductors 6. Typically gasses or solids. 10
The Periodic Table: Metals, Nonmetals, and Metalloids Group VIIA nonmetals halogens F, Cl, Br, I 11
The Periodic Table: Metals, Nonmetals, and Metalloids Group VIA nonmetals Chalcogens O, S, Se, Te 1
The Periodic Table: Metals, Nonmetals, and Metalloids Group VIIIA nonmetals noble, inert or rare gases He, Ne, Ar, Kr, Xe, Rn 13
The Periodic Table: Metals, Nonmetals, and Metalloids Stair step function on periodic table separates metals from nonmetals. Metals are to the left of stair step. Approximately 80% of the elements Nonmetals are to the right of stair step. Approximately 0% of the elements Metalloids have one side of the box on the stair step. Properties between metals and nonmetals 14
The Periodic Table: Metals, Nonmetals, and Metalloids Periodic trends in metallic character More Metallic More Metallic Periodic Chart 15
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Atoms and Atomic Theory 1. All matter is composed of extremely small, indivisible particles called atoms.. All atoms of a given element have identical properties that differ from those of other elements. 3. Atoms cannot be created, destroyed, or transformed into atoms of another element. 4. Atoms of or more elements can combine to form compounds. These combine in fixed proportions 5. Chemical Reactions rearrange and recombine atoms but do not destroy them. 17
Fundamental Particles Three fundamental particles make up atoms. The following table lists these particles together with their masses and their charges. Particle Mass (amu) Charge Electron (e - ) 0.00054858-1 Proton (p,p + ) 1.0073 +1 Neutron(n,n 0 ) 1.0087 0 18
Structure of the Atom 1. The atom is mostly empty space.. It contains a very small, dense center called the nucleus. 3. Nearly all of the atom s mass is in the nucleus. 4. The nuclear diameter is 1/10,000 to 1/100,000 times less than atom s radius. 19
Atomic Number The atomic number is equal to the number of protons in the nucleus. Sometimes given the symbol Z. Numbered consecutively on the periodic table The atomic number determines the element. The elements differ from each other by the number of protons in the nucleus. The number of electrons in a neutral atom is also equal to the atomic number. For charged species there are more electrons if it is negative and less electrons if it is positive 0
Mass Number and Isotopes Mass number is given the symbol A. A is the sum of the number of protons and neutrons. Z = proton number N = neutron number A = Z + N A common symbolism used to show mass and proton numbers is A Z E for example 1 6 C, 48 0 Ca, 197 79 Au 14? N, 63? Cu, 18 8? 1
Isotopes Isotopes are atoms of the same element but with different numbers of neutrons. Isotopes have different masses and A values but are the same element. One example of an isotopic series is the hydrogen isotopes. 1 H or protium is the most common hydrogen isotope. one proton and no neutrons H or deuterium is the second most abundant hydrogen isotope. one proton and one neutron 3 H or tritium is a radioactive hydrogen isotope. one proton and two neutrons 3
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Mass Number and Isotopes How many protons and neutrons are in the following? O 3 Na + 11 16 8 18 8 O 38 9 36 9 U U 40 0 8 35 3 16 Ca Br S + 5
Mass Number and Isotopes Give the number of protons, neutrons and electrons and the correct element symbol 4 1? 00 79 15 7?? 6
Atomic Mass The atomic mass of an element on the periodic table is the weighted average of the masses of its stable isotopes For example H = 1.008 amu Calcium = 40.078 amu We will use these masses later for chemical calculations 7
The role of the electron Bohr s Planetary Model of the atom: 1. Atom has a number of discrete energy levels (orbits, shells) in which an electron may exist As the orbital radius increases so does the energy 1<<3<4<5... 1 3 8
The role of the electron. An electron may move from one energy level (orbit) to another. Radiation is emitted or absorbed Energy is absorbed when electrons jump to higher orbits. n = to n = 4 for example Energy is emitted when electrons fall to lower orbits. n = 4 to n = 1 for example 9
Atomic Spectra and the Bohr Atom The principal quantum number has the symbol n. n = 1,, 3, 4,... shells n = K, L, M, N,... The electron s energy depends principally on n. 30
The role of the electron 31
The role of the electron 3. Each sell contains a region where electrons move in a circular orbit around the nucleus Atomic Orbital (sub shell) Atoms have electrons in s, p, d, or f orbitals. 3
Atomic Orbitals Every orbital can hold up to two electrons. The two electrons are designated as having one spin up and one spin down The number of orbitals per n level is given by n. The maximum number of electrons per n level is n. The value is n because of the two paired electrons. 33
Electrons per shell Energy Level # of Orbitals Max. # of e - n n n 1 1 (s) 4 (s,p) 8 3 9 (s,p,d) 18 4 16 (s,p,d,f ) 3 34
Atomic Orbitals s orbital properties: There is one s orbital per n level. 1s, s, 3s, s orbitals are spherical 35
Atomic Orbitals p orbital properties: The first p orbitals appear in the n = shell. p, 3p, 4p. p orbitals are peanut or dumbbell shaped. There are 3 p orbitals per n level Each orbital holds electrons, 6 total in the p orbitals 36
Atomic Orbitals d orbital properties: The first d orbitals appear in the n = 3 shell. (3d,4d ) There are 5 d orbitals per n level. With electrons per orbital There are 10 electrons In a d orbital 37
Atomic Orbitals f orbital properties: The first f orbitals appear in the n = 4 shell. (4f, 5f, 6f ) There are seven f orbitals per n level.. electrons per level 14 electrons total 38
Electron Configurations 39
The Periodic Table and Electron Configurations Use the periodic chart to figure out how the shells fill up. 40
The Periodic Table and Electron Configurations Use the periodic chart to figure out how the shells fill up. 41
The Periodic Table and Electron Configurations 1 st row elements. 1s Configuration 1 H He 1s 1s 1 4
The Periodic Table and Electron Configurations nd row elements. (Hund s rule) 3 4 5 6 7 8 9 10 C O 1s s Li Be B p N F Ne Configuration 1s 1s 1s 1s 1s 1s 1s 1s s s s s 1 s s s s p p 1 p p p p 3 4 5 6 43
The Periodic Table and Electron Configurations 3 rd row elements 11 1 13 14 15 16 17 18 Na Mg Al Si P S Cl Ar 3s 3p Configuration [ Ne] 1 [ Ne] 3s [ Ne] [ Ne] 3s [ Ne] 1 [ Ne] 3s 3p [ Ne] [ Ne] 3s 3p [ Ne] 3 [ Ne] 3s 3p [ Ne] 4 [ Ne] 3s 3p [ Ne] 5 [ Ne] 3s 3p [ Ne] 6 [ Ne] 3s 3p 44
The Periodic Table and Electron Configurations 4 th row elements 3d 4p Configuration [ ] [ ] 1 Ar Ar 19 K 45
The Periodic Table and Electron Configurations 19 0 K Ca 3d 4p Configuration [ Ar] [ Ar] [ ] [ ] Ar Ar 1 46
The Periodic Table and Electron Configurations 19 0 1 K Ca Sc [ Ar] [ Ar] [ Ar] [ Ar] You do it! 3d 4p Configuration 1 47
The Periodic Table and Electron Configurations 19 0 1 K Ca Sc 3d 4p Configuration [ Ar] [ Ar] [ Ar] [ Ar] [ ] [ ] 1 Ar Ar 3d 1 48
The Periodic Table and Electron Configurations 19 0 1 K Ca Sc Ti [ Ar] [ Ar] [ Ar] [ Ar] [ Ar] [ Ar] You do it! 3d 4p Configuration 1 3d 1 49
The Periodic Table and Electron Configurations 19 0 1 K Ca Sc Ti 3d 4p Configuration [ Ar] [ Ar] [ Ar] [ Ar] [ Ar] [ Ar] [ ] [ ] Ar Ar 3d 1 3d 1 50
The Periodic Table and Electron Configurations 19 0 1 3 K Ca Sc Ti V 3d 4p Configuration [ Ar] [ Ar] [ Ar] [ Ar] [ Ar] [ Ar] [ Ar] [ Ar] [ ] [ ] 3 Ar Ar 3d 1 3d 3d 1 51
The Periodic Table and Electron Configurations 19 0 1 3 4 K Ca Sc Ti V Cr [ Ar] [ Ar] [ Ar] [ Ar] [ Ar] [ Ar] [ Ar] [ Ar] [ Ar] [ Ar] [ Ar] [ Ar] There is an extra measureof with half 3d 4p Configuration stability associated - filled and completelyfilled orbitals. 1 1 3d 3d 3d 3d 1 5 3 5
The Periodic Table and Electron Configurations 3d 4p Configuration [ ] [ ] 5 Ar Ar 5 Mn 3d 53
The Periodic Table and Electron Configurations 6 Mn [ Ar] [ Ar] 5 Fe You do it! 3d 4p Configurat ion 3d 5 54
The Periodic Table and Electron Configurations 5 6 Mn Fe 3d 4p Configurat ion [ Ar] [ Ar] [ ] [ ] 6 Ar Ar 3d 3d 5 55
The Periodic Table and Electron Configurations 5 6 7 Mn Fe Co 3d 4p Configuration [ Ar] [ Ar] [ Ar] [ Ar] [ ] [ ] 7 Ar Ar 3d 3d 5 3d 6 56
The Periodic Table and Electron Configurations 5 6 7 8 Mn Fe Co Ni 3d 4p Configuration [ Ar] [ Ar] [ Ar] [ Ar] [ Ar] [ Ar] [ ] [ ] 8 Ar Ar 3d 3d 3d 5 3d 6 7 57
The Periodic Table and Electron Configurations 5 6 7 8 9 Mn Fe Co Ni [ Ar] [ Ar] [ Ar] [ Ar] [ Ar] [ Ar] [ Ar] [ Ar] Cu You do it! 3d 4p Configuration 3d 3d 3d 3d 5 6 7 8 58
The Periodic Table and Electron Configurations 5 6 7 8 9 Mn Fe Co Ni Cu 3d 4p Configuration [ Ar] [ Ar] [ Ar] [ Ar] [ Ar] [ Ar] [ Ar] [ Ar] [ Ar] [ Ar] Another exception like Cr and for essentially the same reason. 1 3d 3d 3d 3d 3d 5 7 8 10 6 59
The Periodic Table and Electron Configurations 5 6 7 8 9 30 Mn Fe Co Ni Cu Zn 3d 4p Configuration [ Ar] [ Ar] [ Ar] [ Ar] [ Ar] [ Ar] [ Ar] [ Ar] [ Ar] [ Ar] [ ] [ ] 10 Ar Ar 3d 1 3d 3d 3d 3d 5 3d 10 60 6 7 8
The Periodic Table and Electron Configurations 3d 4p Configurat ion 10 1 [ Ar] [ Ar] 3d 31Ga 4p 61
The Periodic Table and Electron Configurations Ga [ Ar] [ Ar] Ge You do it! 3d 4p Configurat ion 31 3 3d 10 4p 1 6
The Periodic Table and Electron Configurations 31 3 Ga Ge 3d 4p Configuration 10 1 [ Ar] [ Ar] 3d 4p 10 [ Ar] [ Ar] 3d 4p 63
The Periodic Table and Electron Configurations 31 3 33 Ga Ge As 3d 4p Configuration [ Ar] 10 1 [ Ar] 3d 4p [ Ar] 10 [ Ar] 3d 4p [ Ar] 10 3 [ Ar] 3d 4p 64
The Periodic Table and Electron Configurations 31 3 33 34 Ga Ge As Se [ Ar] [ Ar] [ Ar] [ Ar] [ Ar] [ Ar] You do it! 3d 4p Configuration 3d 3d 3d 10 10 10 4p 4p 1 4p 3 65
The Periodic Table and Electron Configurations 31 3 33 34 Ga Ge As Se 3d 4p Configuration [ Ar] 10 [ Ar] 3d 1 4p [ Ar] 10 [ Ar] 3d 4p [ Ar] 10 [ Ar] 3d 3 4p [ Ar] 10 [ Ar] 3d 4 4p 66
The Periodic Table and Electron Configurations 31 3 33 34 35 Ga Ge As Se Br 3d 4p Configuration [ Ar] 10 [ Ar] 3d 1 4p [ Ar] 10 [ Ar] 3d 4p [ Ar] 10 [ Ar] 3d 4p [ Ar] 10 [ Ar] 3d 4p [ Ar] 10 [ Ar] 3d 5 4p 3 4 67
The Periodic Table and Electron Configurations 31 3 33 34 35 36 Ga Ge As Se Br Kr 3d 4p Configurat ion [ Ar] 10 [ Ar] 3d 1 4p [ Ar] 10 [ Ar] 3d 4p [ Ar] 10 [ Ar] 3d 3 4p [ Ar] 10 [ Ar] 3d 4 4p [ Ar] 10 [ Ar] 3d 5 4p [ Ar] 10 [ Ar] 3d 6 4p 68
More About the Periodic Table Electron configurations similar leads to similar properties. Noble Gases All of them have completely filled electron shells. Since they have similar electronic structures, their chemical reactions are similar. He 1s Ne [He] s p 6 Ar [Ne] 3s 3p 6 Kr [Ar] 4p 6 Xe [Kr] 5s 5p 6 Rn [Xe] 6s 6p 6 69
More About the Periodic Table Representative Elements Are the elements in A groups on periodic chart. These elements will have their last electron in an outer s or p orbital. These elements have fairly regular variations in their properties. 70
More About the Periodic Table d-transition Elements Elements on periodic chart in B groups. Sometimes called transition metals. Each metal has d electrons. ns (n-1)d configurations These elements make the transition from metals to nonmetals. Exhibit smaller variations from row-to-row than the representative elements. 71
More About the Periodic Table f - transition metals Sometimes called inner transition metals. Electrons are being added to f orbitals. Electrons are being added two shells below the valence shell! Consequently, very slight variations of properties from one element to another. Outermost electrons have the greatest influence on the chemical properties of elements. 7