DECIMAL CLASSIFICATION 
546-547 Inorganic and organic chemistry 
[norganic chemistry 
Nonmetallic elements 
Hydrogen 
Halogen group 
Chlorin 
Bromin 
Iodin 
Fluorin 
Nitrogen group 
Phosphorus 
Arsenic 
Oxygen group 
Oxygen 
Sulfur: 
Selenium 
Tellurium 
Carbon group 
Carbon 
Boron 
Silicon 
Helium group 
Helium 
Neon 
Argon 
Krypton 
Xenon 
Metals 
Alkali group 
Potassium 
Sodium 
Lithium 
Rubidium 
Caesium 
546 
I 
12 
13 
14 
I§ 
161 
17 
18 
I01 
> 
21 
22 
23 
247 
25 
26 
27 
28 
20 
291 
202 
293 
294 
295 
3 
21 
.32 
33 
34 
35 
36 
37 
38 
39 
a4 
Alkalin earths 
Calcium and magnesium groups considerd together 
Calcium 
Strontium 
Barium 
Radium See also 530.7 Radioactivity; 541.38 Radiochemistry 
Magnesium group 
Beryllium or glucinum 
Magnesium 
Zinc 
Cadmium 
41 
42 
43 
1432 
44 
45 
«46 
47 
.48 
40