Page 47 - Curriculum Visions Dynamic Book

Hydrogen did not seem to fit into the table,
so he placed it in a box on its own. Otherwise
the elements were all placed horizontally.
When an element was reached with properties similar to the first one in the top row, a second row was started. By following this rule, similarities among the elements can be found by reading up and down. By reading across the rows, the elements progressively increase their atomic number. This number indicates the number of positively charged particles (protons) in the nucleus of each atom. This is also the number of negatively charged particles (electrons) in
the atom.
The chemical properties of an element depend on the number of electrons in the outermost shell.
Atoms can form compounds by sharing electrons in their outermost shells. This explains why atoms with a full set of electrons (like helium, an inert gas) are unreactive, whereas atoms with
an incomplete electron shell (such as chlorine) are very reactive. Elements can also combine by the complete transfer of electrons from metals to non- metals and the compounds formed contain ions.
Radioactive elements lose particles from their nucleus and electrons from their surrounding shells. As a result their atomic number changes
and they become new elements.
(9) (10)
(11) (12)
3 4 5 6 78or0
(13) (14) (15) (16) (17) (18)
Helium 4
5 6 7 8 9 10
B C N O F Ne
Boron Carbon Nitrogen Oxygen Fluorine Neon 11 12 14 16 19 20
13 14 15 16 17 18
Al Si P S Cl Ar
Aluminium Silicon Phosphorus Sulphur Chlorine Argon 27 28 31 32 35 40
27 28 29 30 31 32 33 34 35 36
e Co Ni Cu Zn Ga Ge As Se Br Kr
Cobalt Nickel Copper Zinc Gallium Germanium Arsenic Selenium Bromine Krypton 59 59 64 65 70 73 75 79 80 84
45 46 47 48 49 50 51 52 53 54
u Rh Pd Ag Cd In Sn Sb Te I Xe
ium Rhodium Palladium Silver Cadmium Indium Tin Antimony Tellurium Iodine Xenon 1 103 106 108 112 115 119 122 128 127 131
77 78 79 80 81 82 83 84 85 86
s Ir Pt Au Hg Tl Pb Bi Po At Rn
m 0
8
Iridium Platinum Gold 192 195 197
109 110 111
Mercury 201
112
Thallium 204
Lead Bismuth 207 209
Ununquadium (289)
Polonium (209)
Ununhexium (289)
Astatine (210)
Radon (222)
Ununoctium (293)
s Mt Uun Uuu Uub
Uuq
Uuh
Uuo
m Meitnerium Ununnilium Unununium Ununbium 5) (266) (272) (272) (277)
61 62 63 64 65 66 67 68 69 70
d Pm Sm Eu Gd Tb Dy Ho Er Tm Yb
ium Promethium Samarium Europium Gadolinium Terbium Dysprosium Holmium Erbium Thulium Ytterbium 4 (145) 150 152 157 159 163 165 167 169 173
93 94 95 96 97 98 99 100 101 102
U Np Pu Am Cm Bk Cf Es Fm Md No
um Neptunium Plutonium Americium Curium Berkelium Californium Einsteinium Fermium Mendelevium Nobelium 8) (237) (244) (243) (247) (247) (251) (252) (257) (258) (259)
114
116
118
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