1、1,Department of Chemistry Hon Man Lee (李漢文) Tel: 3517 (office); 3523 (lab) 3/F Chemistry Building 自然科學(xué)概論(化學(xué)) .tw/leehm/contents/enter.htm .tw,2,Atomic Theory and Atomic Structure,原子理論與原子結(jié)搆,3,Atomic Theory of Matter John Dalton in 1808,All matter is composed of smal

2、l particles called atoms. An atom (原子): indivisible, retain its identity during chemical reactions An element (元素): A type of matter of only one kind of atom, e.g. hydrogen (H), oxygen (O),4,What is a compound?,A compound(化合物): A type of matter of atoms of two or more elements chemically combined in

3、 fixed proportions, e.g. water (H2O, CH4) (ii) molecular compound (分子化合物), e.g. H2O (iii) ionic compound (離子化合物), e.g. sodium chloride, 氯化鈉 (Na+ Cl-),5,What is a chemical reaction?,A chemical reaction (化學(xué)反應(yīng)): Rearrangement of the atoms present in the reactant to give new chemical combinations presen

4、t in the product Equation (反應(yīng)式): 2H2 + O2 2H2O Reactant Product,6,A balanced equation,Atoms are not created, destroyed, or broken! H2 + O2 /- NaCl A balanced equation H2 + O2 /- H2O No. of H atoms in right hand side = No. of H atoms in left hand side Same to the atoms of other elements,7,Sub-atomic

5、particles,Dalton did not know there were sub-atomic particles in the atoms. Dalton atomic theory in 1808.,8,The structure of the atom,Discovery of the electron (1897): J. J. Thomson (British) The nuclear model of the atom (1911): Ernest Rutherford (British),9,The structure of the atom,Atom: nucleus

6、(原子核) + electrons (電子) Nucleus : neutrons (中子), protons (質(zhì)子), For example, H = 1 proton + 1 electron,10,The hydrogen atom,Electron: mass = 9.10939 x 10-31 kg, charge = -1 Proton: mass = 1.67262 x 10-27 kg, charge = +1 Neutron: mass = 1.67493 x 10-27 kg, charge = 0,Mass = 質(zhì)量,Isotope (同位素),重氫, 氘,1. Ma

7、ss of p/n = 1833 e 2. mass of proton mass of neutron,Notice the accuracy!,11,Isotopes (同位素),atoms whose nuclei have same atomic numbers but different mass numbers same number of protons but different numbers of neutrons e.g. 1H : 1 p + 0 n2H : 1p + 1n,12,Nuclide symbol,Atomic number number of proton

8、s in the nucleus Identity (身份) of the element (元素) Mass number number of protons + neutrons in the nucleus In a neutral atom: number of protons = number of electrons,13,Exercise,Q.1 How many protons and neutrons in 15N?,Q2. How many protons and neutrons in 14N,Q4. A nucleus consists of 17 protons an

9、d 18 neutrons. What is its nuclide symbol?,7p, 8n,7p, 7n,Q3. How many protons and neutrons in 23Na,11p, 12n,They are isotopes,14,15,Some Common Transition Metal Elements (過渡金屬元素),16,Relative Atomic Masses (相對原子質(zhì)量),Mass Number = numbers of protons + neutrons (整數(shù)) Relative Atomic Masses (相對原子質(zhì)量) (非整數(shù))

10、 Unit = Atomic Mass Unit (amu) Standard 1 amu = mass of 1H (old), no neutron 1 amu = 1/12 of the mass of a 12C atom (new), 6p, 6n,17,Atomic Weight (原子重量),= the average atomic mass for the naturally occurring element, in amu Consideration for the presence of isotopes,18,Atomic Weight,Chromium (鉻) , C

11、r, has four isotopes Atomic number = 24,19,Atomic weight of chromium,20,What is the atomic weight of chlorine?,Atomic weight,21,Periodic Table of Elements (元素週期表),1869 Dmitri Mendeleev (Russian) J. Lothar Meyer (German) Row (列) = period (期) Column (欄) = group (族),22,Periodic Table of Elements (元素週期表

12、),Arrange elements in order of atomic numbers Elements in the same group have similar properties e.g.Li, Na, Kreactive metalsgroup 1 Cl, F, Brreactive gasgroup 7 He, Ne, Arinert gasgroup 8,23,A periodic table,Alkali metals 鹼金屬,Other metals,1,2,Alkali earth metals 鹼土金屬,Noble gases 隋性氣體,Transition met

13、als 過渡金屬,Halogens 鹵素,Rare earth metals 稀土金屬,Other nonmetals,solid,liquid,Gas,Synthetic,Lanthanides 鑭系 Actinides 系,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,24,Group (族),Elements in the same group have similar properties Group 1: alkali metal 鹼金屬 Group 2: alkali earth metal 鹼土金屬 Group 7A (17): halogen 鹵素 Group 8A (18): noble gas/inert gas 隋性氣體,25,Period (期),PeriodNo. of elements 1 2H, He 2 8 Li Ne 38 Na Ar 418 K Kr 5 18 Rb Xe 632 Cs Rn 7incomplete Fr ,26,Blocks,Transition Metal 過渡金屬 (d-block) Inner-transitio