As - Arsenic

This metaloid has been known for its toxic properties since the 1200's.

Atomic number - 33 Density g/mL 5 .72

Atomic weight u 74 .9216 Melting point K 1091

Bonding radius A 1 .2 Boiling point K 886

Atomic radius A 1 .33 Heat of vaporization kJ/mol 34 .76

Ionization Potential V 9 .81 Heat of fusion kJ/mol -

Electronegativity - 2 .18 Specific heat J/gK 0 .33

The oxide is mildly acidic.
Crystal are rhombohedral.

Electron config. : [Ar] 3d¹⁰ 4s² 4p³

Isotopes of As: Click mass number for decay process, product for element page.

065 0.19 sec EC,9.400 MeV Ge-65 64.949436	066 0.10 sec EC,9.800 MeV Ge-66 65.944368	067 42.5 sec EC,6.010 MeV Ge-67 66.939194	068 151.6 sec EC,8.100 MeV Ge-68 67.936789	069 15.2 min EC,4.010 MeV Ge-69 68.932280	070 52.6 min EC,6.220 MeV Ge-70 69.930928	071 65.28 hr EC,2.013 MeV Ge-71 70.927113
072 26.0 hr EC,4.356 MeV Ge-72 71.926753	073 80.30 da EC,1.593 MeV Ge-73 72.923825	074 17.77 da B-/EC,2.562 Se-74/Ge-74 73.923929	075 100% Stable 74.921596	076 1.0778 da B-,2.962 MeV Se-76 75.922394	077 38.83 hr B-,2.862 MeV Se-77 76.920647	078 90.7 min B-,4.210 MeV Se-78 77.921828
079 9.01 min B-,2.281 MeV Se-79 78.920948	080 15.2 sec B-,5.641 MeV Se-80 79.922578	081 33.3 sec B-,3.856 MeV Se-81 80.922132	082 19.1 sec B-,7.270 MeV Se-82 81.924508	083 13.4 sec B-,5.460 MeV Se-83 82.924980	084 4.02 sec B-/B-n,9.900 Se-84/Se-83 83.929038	085 2.002 sec B-/B-n,8.900 Se-85/Se-84 84.931829
086 0.945 sec B-/B-n,11.100 Se-86/Se-85 85.936231	087 0.49 sec B-/B-n,10.300 Se-87/Se-86 86.939559	MASS abund. Halflife Particle, Energy Decay Product(s) Isotopic Mass

Atomic number	-	33		Density	g/mL	5	.72
Atomic weight	u	74	.9216	Melting point	K	1091
Bonding radius	A	1	.2	Boiling point	K	886
Atomic radius	A	1	.33	Heat of vaporization	kJ/mol	34	.76
Ionization Potential	V	9	.81	Heat of fusion	kJ/mol	-
Electronegativity	-	2	.18	Specific heat	J/gK	0	.33
The oxide is mildly acidic.				Crystal are rhombohedral.
Electron config. : [Ar] 3d¹⁰ 4s² 4p³