Answer:
Element Valence
1 Hydrogen (-1), +1
2 Helium 0
3 Lithium +1
4 Beryllium +2
5 Boron -3, +3
6 Carbon (+2), +4
7 Nitrogen -3, -2, -1, (+1), +2, +3, +4, +5
8 Oxygen -2
9 Fluorine -1, (+1)
10 Neon 0
11 Sodium +1
12 Magnesium +2
13 Aluminum +3
14 Silicon -4, (+2), +4
15 Phosphorus -3, +1, +3, +5
16 Sulfur -2, +2, +4, +6
17 Chlorine -1, +1, (+2), +3, (+4), +5, +7
18 Argon 0
19 Potassium +1
20 Calcium +2
21 Scandium +3
22 Titanium +2, +3, +4
23 Vanadium +2, +3, +4, +5
24 Chromium +2, +3, +6
25 Manganese +2, (+3), +4, (+6), +7
26 Iron +2, +3, (+4), (+6)
27 Cobalt +2, +3, (+4)
28 Nickel (+1), +2, (+3), (+4)
29 Copper +1, +2, (+3)
30 Zinc +2
31 Gallium (+2). +3
32 Germanium -4, +2, +4
33 Arsenic -3, (+2), +3, +5
34 Selenium -2, (+2), +4, +6
35 Bromine -1, +1, (+3), (+4), +5
36 Krypton 0
37 Rubidium +1
38 Strontium +2
39 Yttrium +3
40 Zirconium (+2), (+3), +4
41 Niobium (+2), +3, (+4), +5
42 Molybdenum (+2), +3, (+4), (+5), +6
43 Technetium +6
44 Ruthenium (+2), +3, +4, (+6), (+7), +8
45 Rhodium (+2), (+3), +4, (+6)
46 Palladium +2, +4, (+6)
47 Silver +1, (+2), (+3)
48 Cadmium (+1), +2
49 Indium (+1), (+2), +3
50 Tin +2, +4
51 Antimony -3, +3, (+4), +5
52 Tellurium -2, (+2), +4, +6
53 Iodine -1, +1, (+3), (+4), +5, +7
54 Xenon 0
55 Cesium +1
56 Barium +2
57 Lanthanum +3
58 Cerium +3, +4
59 Praseodymium +3
60 Neodymium +3, +4
61 Promethium +3
62 Samarium (+2), +3
63 Europium (+2), +3
64 Gadolinium +3
65 Terbium +3, +4
66 Dysprosium +3
67 Holmium +3
68 Erbium +3
69 Thulium (+2), +3
70 Ytterbium (+2), +3
71 Lutetium +3
72 Hafnium +4
73 Tantalum (+3), (+4), +5
74 Tungsten (+2), (+3), (+4), (+5), +6
75 Rhenium (-1), (+1), +2, (+3), +4, (+5), +6, +7
76 Osmium (+2), +3, +4, +6, +8
77 Iridium (+1), (+2), +3, +4, +6
78 Platinum (+1), +2, (+3), +4, +6
79 Gold +1, (+2), +3
80 Mercury +1, +2
81 Thallium +1, (+2), +3
82 Lead +2, +4
83 Bismuth (-3), (+2), +3, (+4), (+5)
84 Polonium (-2), +2, +4, (+6)
85 Astatine ?
86 Radon 0
87 Francium ?
88 Radium +2
89 Actinium +3
90 Thorium +4
91 Protactinium +5
92 Uranium (+2), +3, +4, (+5), +6
Explanation:
Groups 1A, 2A, and 3A, 4A, 5A, 6A, 7A, adn 8A are easy to figure out the valence electrons. The metals (groups 1A and 2A, 3A) all want to give their electrons away so they loose their electrons to get to the perfects state, the octet (having 8 valence electrons). Whereas, the non-metals (those elements in groups 4A, 5A, 6A, 7A, and 8A) are like gaining electrons in order to come to arrive at the octet state. Group 4A is a little bit harder (containing Carbon) because it can give up to 4 electrons and can loose up to 4 electrons. The rest of the periodic table (the transitional metals, your lanthanides and actinides) are much harder to figure out the valences of because many of them can have numerous charges. Those are generally given to you unless otherwise asked to be figured out.
