2) Complete the following table. Take into account that all the atoms in it are neutral atoms: Copper Uranium Phosphorus 15 16

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1 1) Describe Thomson's atomic model and draw it. THOMSON (1897): an atom is a solid sphere positively charged matter with embedded. 2) Complete the following table. Take into account that all the atoms in it are neutral atoms: Element Z A Copper Uranium Phosphorus A (number nucleons) = Z (number ) + N (number ) N = A Z Z = A N

2 Element Z A Boron =6 Copper = =36 Uranium = 143 Phosphorus = Lead =122 3) Complete the following table. Take into account that all the atoms in it are ions: Element Z A Zinc Lead A (number nucleons) = Z (number ) + N (number ) N = A Z Z = A N A cation has as many positive charges as the it has lost. An anion has as many negative charges as the it has gained. Element Z A 32 16= = 16 Sulfur = = 18 Zinc = =34 Gold = =76 = 118 Chlorine = = = 18 Lead = =82

3 4) a) Find, between the following elements, as many couples isotopes as possible: b) Indicate the number, and for each atom in each couple isotopes. a) If two atoms are isotopes: They have the same value Z (number in the nucleus) because they belong to the same chemical element. Their values A (number nucleons) are different because they have a different number. So the isotope couples are: and and and b) = = = = = = 2 1 5) Write down the electron configuration the following elements: K (Z = 19), Sn (Z = 50), Co (Z = 27), Ne (Z = 10) K (Z = 19): 1s 2 2s 2 2p 6 3s 2 3p 6 4s 1 Sn (Z = 50): 1s 2 2s 2 2p 6 3s 2 3p 6 4s 2 3d 10 4p 6 5s 2 4d 10 5p 2 Co (Z = 27): 1s 2 2s 2 2p 6 3s 2 3p 6 4s 2 3d 7 Ne (Z = 10): 1s 2 2s 2 2p 6

4 6) Write down the valence the elements in the previous question. How many valence does each element have? Element Valence valence K 4s 1 1 Sn 5s 2 5p 2 4 Co 4s 2 2 Ne 2s 2 2p 6 8 7) Describe the ionic bond between: a) K (Z = 19) and Cl (Z = 17) b) Mg (Z = 12) and Cl (Z = 17) a) Element Electron configuration Valence 1s 2 2s 2 2p 6 3s 2 3p 6 4s 1 1 1s 2 2s 2 2p 6 3s 2 3p 5 7 Ion Formula KCl b) Element Electron configuration Valence 1s 2 2s 2 2p 6 3s 2 2 1s 2 2s 2 2p 6 3s 2 3p 5 7 Ion Formula MgCl 2

5 8) Describe Rutherford's atomic model and draw it. RUTHERFORD (1911): nuclear model with two distinct areas: NUCLEUS: o Positively charged. o Contains most the mass the atom. o It was suggested that in it were the and. Neutrons had not been discovered yet. CORTEX: with rotating in circular orbits. Between the nucleus and the cortex there was a lot space which was a vacuum.

6 9) Complete the following table. Take into account that all the atoms in it are neutral atoms: Element Z A Mercury Nitrogen 7 7 A (number nucleons) = Z (number ) + N (number ) N = A Z Z = A N Element Z A Beryllium = 5 Mercury = 121 Iodine =74 Nitrogen = = 14 Tin = 69

7 10) Complete the following table. Take into account that all the atoms in it are ions: Element Z A Iron Calcium A (number nucleons) = Z (number ) + N (number ) N = A Z Z = A N A cation has as many positive charges as the it has lost. An anion has as many negative charges as the it has gained. Element Z A Platinum = = = 117 Iron =30 Nitrogen = = =7 Bromine = =44 Calcium = )a) Find, between the following elements, as many couples isotopes as possible: b) Indicate the number, and for each atom in each couple isotopes.

8 a) If two atoms are isotopes: They have the same value Z (number in the nucleus) because they belong to the same chemical element. Their values A (number nucleons) are different because they have a different number. So the isotope couples are: and and and b) = = = = = = ) Write down the electron configuration the following elements: Sr (Z = 38), Ag (Z = 47), Si (Z = 14), Xe (Z = 54) Sr (Z = 38): 1s 2 2s 2 2p 6 3s 2 3p 6 4s 2 3d 10 4p 6 5s 2 Ag (Z = 47): 1s 2 2s 2 2p 6 3s 2 3p 6 4s 2 3d 10 4p 6 5s 2 4d 9 Si (Z = 14): 1s 2 2s 2 2p 6 3s 2 3p 2 Xe (Z = 54): 1s 2 2s 2 2p 6 3s 2 3p 6 4s 2 3d 10 4p 6 5s 2 4d 10 5p 6 13) Write down the valence the elements in the previous question. How many valence does each element have?

9 Element Valence valence Sr 5s 2 2 Ag 5s 2 2 Si 3s 2 3p 2 4 Ne 5s 2 5p ) What type link (bond) is formed between the following atoms? a) Two hydrogen atoms. b) Hydrogen and Chlorine. c) Potassium and Fluorine. d) A lot iron atoms. a) Covalent bond (two non-metal atoms combined). b) Covalent bond (two non-metal atoms combined). c) Ionic bond (a metal atom and a non-metal one combined). d) Metallic bond which explains the structure pure metallic elements crystals. 15) Identify the type bond in each substance: Substance Melting point Boiling point Water solubility Electrical conductivity X Yes Yes, but only when it is dissolved in water. Y No Yes Z No No X = ionic bond Y = metallic bond Z = covalent bond 16) Describe the bond between: a) K (Z = 19) and O (Z = 8) b) Mg (Z = 12) and O (Z = 8) c) K (Z = 19) and Cl (Z = 17) d) ) Mg (Z = 12) and Cl (Z = 17) e) A magnesium ( 12 Mg) crystal f) g)

10 a) Element Electron configuration Valence 1s 2 2s 2 2p 6 3s 2 3p 6 4s 1 1 1s 2 2s 2 2p 4 6 Ion Formula K 2 O b) Element Electron configuration Valence 1s 2 2s 2 2p 6 3s 2 2 1s 2 2s 2 2p 4 6 Ion Formula MgO

11 c)

12 d) Element Electron configuration Valence 1s 2 2s 2 2p 6 3s 2 2 1s 2 2s 2 2p 6 3s 2 3p 5 7 Ion Formula MgCl 2 e) ELEMENT ELECTRON CONFIGURATION VALENCE ION FORMULA ELECTRONS 2 Mg

13 f) ELEMENT ELECTRON CONFIGURATION VALENCE NEED FORMULA ELECTRONS H 2 LEWIS DIAGRAM g) ELEMENT ELECTRON CONFIGURATION VALENCE NEED FORMULA ELECTRONS H 2 O LEWIS DIAGRAM