1. C HAPTER 2 A TOMS, M OLECULES AND I ONS Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

2. C HAPTER 2 ( P.49-68) Atomic number, mass number and isotopes. The periodic table. Molecules and ions. Chemical formulas. Naming compounds. Tables 2.1- 2.2 – 2.3 – 2.4 - 2.5 – 2.6 – 2.7 Examples 2.1- 2.2 – 2.3 – 2.4 – 2.5 – 2.6 – 2.7 – 2.8 – 2.9

3. Elements: are composed of extremely small particles called atoms. { لاَ يَعْزُبُ عَنْهُ مِثْقَالُ ذَرَّةٍ فِي السَّمَاوَاتِ وَلاَ فِي الأَرْضِ وَلاَ أَصْغَرُ مِن ذَلِكَ وَلاَ أَكْبَرُ إِلاَّ فِي كِتَابٍ مُّبِينٍ} (سبأ: 3). Atom: is the basic unit of an element that can enter into chemical combination Atom consist of: Electron (e) (-ve charge) Proton (p) (+ve charge) Neutron (n) (neutral) Subatomic Particles

4. mass p = mass n = 1840 x mass e - 2.2

5. 2.3 A TOMIC NUMBER, MASS NUMBER AND ISOTOPES.

6. Atomic number (Z) = number of protons in nucleus. X A Z H 1 1 C 12 6 Kr 83 36 Mass Number Atomic Number Element Symbol 2.3 Atomic number, Mass number and Isotopes In the neutral atom: the No. of protons is equal the No. of electrons. So the atomic number also= No. of electrons. Mass number (A) = number of protons + number of neutrons = atomic number (Z) + number of neutron No. of neutron= mass No. (A)- atomic No. (Z) He 4 2 Examples:

7. elements Atomic Number (Z)11 8680 Mass Number (A)20221714200 No. of electrons (e)11 8680 No. of protons (p)11 8680 No. of neutrons (n)91198120 Give the number of protons, neutrons, and electrons in each of the following species: Na 20 11 Na 22 11 O 17 8 C 14 6 Hg 200 80 Define the element X 63 29 ? The element with atomic number 29 is cupper (Cu) and its mass number is 63

8. 6 protons, 8 =(14 - 6) neutrons, 6 electrons Do You Understand Isotopes? How many protons, neutrons, and electrons are in C 14 6 ? How many protons, neutrons, and electrons are in C 11 6 ? 6 protons, 5 =(11 - 6) neutrons, 6 electrons

9. Isotopes are atoms of the same element (X) with different numbers of neutrons in their nuclei H 1 1 H (D) 2 1 H (T) 3 1 U 235 92 U 238 92 C 12 6 C 13 6 C 14 6 examples: Isotopes of an atom have essentially the same chemical behavior. 1 P 1 P 1 P 0 n 1 n 2n Isotopes of Hydrogen

12. Practice Exercise: How many protons, neutrons, and electrons are in the following isotope of copper: 63 Cu? How can I get the atomic number: look at the periodic table → then find the number of p, n & e. P=29 n=34 e=29

13. Allotrope is one of tow or more distinct forms of an element as O 2, O 3. Allotropes O-O (O 2 ) and O 3 Allotropes are different structural forms of the same element and can exhibit quite different physical properties and chemical behaviors.

14. D IAMOND AND G RAPHITE Graphite Diamond the carbon atoms are bonded together in a tetrahedral lattice arrangement. tetrahedral the carbon atoms are bonded together in sheets of a hexagonal lattice arrangement.hexagonal lattice

15. (i.e. how the atoms are arranged ).  allotropes of an element differ on the structure of the same atoms, (i.e. how the atoms are arranged ). (i.e. the composition of subatomic particles in an atom).  isotopes of the element differ on the number of neutrons of the atoms (i.e. the composition of subatomic particles in an atom).

16. 2.4 T HE PERIODIC TABLE.

17. The Periodic Table The periodic Table: is a chart in which elements having similar chemical and physical properties are grouped together. The elements in the modern periodic table are arranged by atomic number

18. Period Group Alkali Metal Noble Gases Halogen Alkaline Earth Metal 2.4 Periodic Table

19. Chemistry In Action Natural abundance of elements in Earth’s crust Natural abundance of elements in human body 2.4

20. 2.5 MOLECULES AND IONS.

21. H2H2 H2OH2ONH 3 CH 4 The monatomic gases are the single atoms of noble gases; He, Ne, Ar, Kr, Xe, Rn. A molecule is an aggregate of two or more atoms in a definite arrangement held together by chemical forces. Diatomic molecule: contains only two atoms H 2, N 2, O 2, Br 2, HCl, CO, NO, KCl Polyatomic molecule: contains more than two atoms O 3, H 2 O, NH 3, CH 4, NaOH Molecule

22. Cation: an ion with a +ve charge (lose electron/s) Na +, K +, Mg 2+ Al 3+, N 3- Anion: an ion with a -ve charge ( Gain electron/s) Ion Monoatomic cation Polyatomic cation Monoatomic anion Cl -, Br -,S 2- Polyatomic anion OH -, PO 4 3- NH 4 + An ion is an atom, or group of atoms, that has a net positive or negative charge.

23. 11 Na 11 protons 11 electrons 11 Na + 11 protons 10 electrons 17 Cl 17 protons 17 electrons 17 Cl - 17 protons 18 electrons Cation anion

24. 13 protons, 10 (13 – 3) electrons 34 protons, 36 (34 + 2) electrons Do You Understand Ions? How many protons and electrons are in ?Al 27 13 3+ How many protons and electrons are in ?Se 78 34 2-

25. 2.5 Different Ions of Some Elements  Metals tend to form cations  Nonmetals tend to form anions

26. P 31 15 3- B 11 5 Au 196 79 Rn 222 86 26 54-26=28 26-2=24 2+00 18-3=15 86

27. 2.6 CHEMICAL FORMULAS.

28. 2.6 الصيغة الجزيئية الصيغة البنائية نموذج الكرة والعصا نموذج ملء الفراغ

29. A molecular formula shows the exact number of atoms of each element in the smallest unit of a substance An empirical formula shows the simplest whole-number ratio of the atoms in a substance H2OH2O H2OH2O molecular empirical C 6 H 12 O 6 CH 2 O O3O3 O N2H4N2H4 NH 2 الصيغة الأولية أبسط صورة للجزئ تعطي نسب وجود الذرات المكونة للجزئ بأصغر نسبة وليس من الضروري أن تعطي العدد الصحيح للذرات الصيغة الجزيئية تحتوي على العدد الصحيح من ذرات كل عنصر يدخل في تركيب أصغر وحده في المادة ( الجزئ ) من الصيغة الجزيئية نستطيع إيجاد الصيغة الأولية والعكس غير صحيح

30.  The Empirical Formula may the same or different from the Molecular Formula  How can we get the Empirical Formula? Answer: Divide all the numbers by the largest Common devisor.  e.g. The empirical formula of H 2 O is H 2 O  e.g. the empirical formula of C 6 H 12 O 6 is CH 2 O (divide the numbers 6, 12 and 6 by the largest common devisor 6) It must be noted that:

32. O H H H H C C Cl H CH 4 O CH 3 OH CHCl 3 or Molecular formula of Methanol Molecular formula of Chloroform Write the Molecular formula of Methanol and Chloroform, using the structural formulas below:

34. Write the empirical formulas for the following molecules if possible: Compounds Name Molecular FormulaEmpirical Formula acetyleneC2H2C2H2 CH glucoseC 6 H 12 O 6 CH 2 O nitrous oxide N2ON2ON2ON2O caffeineC 8 H 10 N 4 O 2 C4H5N2OC4H5N2O

35. ionic compounds consist of a combination of cations and an anions the formula is always the same as the empirical formula the sum of the charges on the cation(s) and anion(s) in each formula unit must equal zero The ionic compound NaCl 2.6 المركبات الأيونية صيغتها الجزيئية مطابقة للصيغة الأولية مجموع شحنة الكاتيونات + شحنة الأنيونات = صفر

36. Formula of Ionic Compounds Al 2 O 3 2 x +3 = +63 x -2 = -6 Al 3+ O 2- CaBr 2 1 x +2 = +22 x -1 = -2 Ca 2+ Br - Na 2 CO 3 2 x +1 = +21 x -2 = -2 Na + CO 3 2- Subscript numeral of cation=the charge of anion Subscript numeral of anion=the charge of cation قاعدة تبادل التكافؤات

38. Problems 2.10 – 2.11 – 2.12 – 2.14 – 2.16 – 2.18 2.26 - 2.34 – 2.36 – 2.44 – 2.46 – 2.50

39. 2.7 NAMING COMPOUNDS.

40. Chemical Nomenclature of Ionic Compounds Chemical Nomenclature of Ionic Compounds nonmetal (anion)Metal (cation) The most reactive metals (green) and the most reactive nonmetals (blue) combine to form ionic compounds.

41. C HEMICAL N OMENCLATURE Mg(OH) 2 magnesium hydroxide KCN potassium cyanide 2.7 BaCl 2 barium chloride K2OK2O potassium oxide –Binary compounds are compounds formed from just two elements –Ternary compounds are compounds formed from three elements. المركبات الأيونية يتكون الإسم من الفلز يليه اللافلز يضاف ide لللافلز المركبات الأيونية يتكون الإسم من الفلز يليه اللافلز يضاف ide لللافلز Ionic Compounds often a metal (cation) + nonmetal (anion) The cation is always named first and the anion second anion (nonmetal), add “ide” to element name

42. Metal (cation) Divalent elements Monovalent elements Lithium (Li + ) Sodium (Na + ) Potassium (K + ) Robidium (Rb + ) Silver (Ag + ) Magnisium (Mg 2+ ) Calcium (Ca 2+ ) Strontium (Sr 2+ ) Barium (Ba 2+ ) Lead (Pb 2+ ) Zinc (Zn 2+ ) trivalent elements Aluminium (Al 3+ ) Galium (Ga 3+ ) Transition metals (Fe 2+ ) iron(II) (Fe 3+ ) iron(III) (Cr 3+ ) chromium (III) (Cu 2+ ) cupper (II) (Cu + ) cupper (I) (Mn 2+ ) manganese(II) (Mn 3+ ) manganese(III) (Mn 4+ ) manganese(IV) (Mn 7+ ) manganese(VII) (Sn 2+ ) stannous or tin(II) (Hg 2 2+ ) mercury(I) (Hg 2+ ) mercury(II) Common name of metal cation: NH 4 + ammonium

43. nonmetal (anion) Hydrogen hydride (H - ) Oxygen oxide (O 2- ) Nitrogen nitride (N 3- )

44. Metals form only type of cation Metals form more than one type of cation (Transition Metals) 1.Group 1A (alkaline Metals): +1 2. Group 2A (alkaline Earth Metals): +2 3. Group 3A: +3 4. Group 5A: -3 (= 5-8) 5. Group 6A: -2 (= 6-8) 6. Group 7A (halogens): -1 (= 7-8) Nonmetals

45. Some common oxygenated anions (SO 4 2- ) sulfate, (SO 3 2- ) sulfite (NO 3 - ) nitrate (NO 2 - ) nitrite (PO 4 3- ) phosphate (PO 3 3- ) phosphite (ClO 4 – ) perchlorate (ClO 3 - ) chlorate (HSO 4 - ) hydrogen sulfate or bisulfate (HPO 4 2- ) hydrogen phosphate or biphosphate (CO 3 2– ) carbonate (H CO 3 – ) hydrogen carbonate or bi carbonate (H 2 PO 4 - ) dihydrogen phosphate كبريتات ات كبريتيت يت

46. FeCl 2 2 Cl - -2 so Fe is +2 iron(II) chloride FeCl 3 3 Cl - -3 so Fe is +3 iron(III) chloride Cr 2 S 3 3 S -2 -6 so Cr is +3 (6/2) chromium(III) sulfide 2.7 Transition metal ionic compounds –indicate charge on metal with Roman numerals –In the Stock system the different cations charge are designated with Roman numerals Transition metal ionic compounds –indicate charge on metal with Roman numerals –In the Stock system the different cations charge are designated with Roman numerals FeCl 2 قاعدة تبادل التكافؤات

47. 2.7

49. Name the following ionic compounds: Cu(NO 3 ) 2 KH 2 PO 4 NH 4 SCN H2O2H2O2 Li 2 SO 3 Ca 3 (PO 3 ) 2 KMnO 4 Cupper(II) nitrate Potassium dihydrogen phosphate Ammonium thiocyanate Hydrogen peroxide Lithium sulfite Calcium phosphite Potassium permenganate Hg 2 Cl 2 Mercury(I) chloride K 2 CrO 4 Potassium chromate Br 2 O 7 Dibromine heptoxide

50. Write formulas for the following ionic compounds: MnO K 2 HPO 4 NH 4 ClO 2 Pb(OH) 2 NaHCO 3 Ba(CN) 2 RbHSO 4 HgBr 2 Manganese(II) oxide Potassium hydrogen phosphate Ammonium chlorite Lead hydroxide Sodium bicarbonate Barium cyanide Rubidium hydrogensulfate Mercury(II) bromide SrH 2 Strontium hydride

51. M OLECULAR C OMPOUNDS DiboraneB2H6B2H6 MethaneCH 4 SilaneSiH 4 AmmoniaNH 3 PhosphinePH 3 WaterH2OH2O Hydrogen sulfideH2SH2S 2- common names of some molecular compounds المركبات الجزيئية تتكون من أشباه فلزات + لا فلزات لا فلزات + لا فلزات معظم المركبات الجزيئية تكون ثنائية العنصر ( تتكون من عنصرين فقط ) بعضها له أسماء شائعه مثل H 2 O, NH 3, CH 4 العنصر الأخير يضاف لنهايته ide المركبات الجزيئية تتكون من أشباه فلزات + لا فلزات لا فلزات + لا فلزات معظم المركبات الجزيئية تكون ثنائية العنصر ( تتكون من عنصرين فقط ) بعضها له أسماء شائعه مثل H 2 O, NH 3, CH 4 العنصر الأخير يضاف لنهايته ide 1- Consists of (metalloid + nonmetal) or (nonmetal + nonmetal) Many molecular compounds are binary compounds 3- last element ends in -ide

52. 4- element further left in periodic table is 1 st (less electronegative) (HCl) H(1A) and Cl(7A), so hydrogen is 1 st, the name is hydrogen chloride 5- element closest to bottom of group is 1 st (less electronegative) (SiC) Si(4A) and C also belongs to (4A),but (Si) is closest to bottom of the group, so silicon is 1 st, the name is silicon carbide 6- if more than one compound can be formed from the same elements, use prefixes to indicate number of each kind of atom. (NO) nitrogen monooxide mononitrogen monoxide (NO 2 ) nitrogen dioxide (N 2 O) dinitrogen monooxide تكتب العناصر الموجوده يسار الجدول الدوري أو الأقرب لليسار أولا. المركبات المحتوية على أكثر من ذرة من نفس العنصر يعبر عن عدد الذرات للعنصر لها باستخدام البادئات اليونانية تكتب العناصر الموجوده يسار الجدول الدوري أو الأقرب لليسار أولا. المركبات المحتوية على أكثر من ذرة من نفس العنصر يعبر عن عدد الذرات للعنصر لها باستخدام البادئات اليونانية dinitrogen tetraoxide Omitted if its in the first element

53. HI hydrogen iodide PF 3 phosphorus trifluoride H2O2H2O2 Hydrogen peroxide N2O4N2O4 dinitrogen tetraoxide NO 2 nitrogen dioxide N2ON2O dinitrogen monooxide Examples of Molecular Compounds 2.7 TOXIC ! Laughing Gas ICl 3 Iodine trichloride

54. Name the following molecular compounds: SO 2 SiCl 4 BrF 7 P 4 O 10 Cl 2 O 7 CH 4 CS 2 Sulpher dioxide Silicon tetrachloride Bromine heptaflouride Tetraphosphorus decoxide Dichlorine heptoxide Methane Carbon disulphide Br 2 O 7 Dibromine heptoxide

55. Write formulas for the following molecular compounds: SF 4 N2O5N2O5 SO 3 Si 2 Br 6 PCl 5 P 4 S 10 N2O2N2O2 Sulphur tetraflouride Dinitrogen pentoxide Sulfur trioxide Disilicon hexabromide Phosphorus pentachloride Tetraphosphorus decasulphide Nitrogen peroxide CO Carbon monoxide IF 7 Iodine heptaflouride

56. Fill the blanks in the following table nameformulaanioncation Barium bicarbonateBa(HCO 3 ) 2 HCO 3 - Ba 2+ Iron(III)nitriteFe (NO 2 ) 3 NO 2 - Fe 3+ Hyrdogen flourideHFF-F- H+H+ Manganise(IV)oxideMnO 2 O 2- Mn 4+ Sodium peroxideNa 2 O 2 O 2 2- Na + Cesium chlorateCsClO 3 ClO 3 - Cs + Lithium nitrideLi 3 NN 3- Li +

57. Page 64 ((+1 ((+2

58. Problems 2.58 – 2.60 – 2.94