Read More
Date: 9-1-2018
![]()
Date: 2-3-2017
![]()
Date: 6-1-2019
![]() |
Occurrence of the group 13 elements
The relative abundances of the group 13 elements are shown in Figure 1.1. The main sources of boron are borax, Na2 [B4O5(OH)4]. 8H2O, and kernite, Na2 [B4O5(OH)=]. 2H2O, with extensive deposits being worked commercially in the Mojave Desert, California. Aluminium is the most abundant metal in the Earth’s crust, and occurs in aluminosilicates (see Section 13.9) such as clays, micas and feldspars, in bauxite (hydrated oxides) and, to a lesser extent, in cryolite, Na3[AlF6]. Gallium, indium and thallium occur in trace amounts as sulfides in various minerals.
|
|
دخلت غرفة فنسيت ماذا تريد من داخلها.. خبير يفسر الحالة
|
|
|
|
|
ثورة طبية.. ابتكار أصغر جهاز لتنظيم ضربات القلب في العالم
|
|
|
|
|
العتبة العباسية المقدسة تقدم دعوة إلى كلية مزايا الجامعة للمشاركة في حفل التخرج المركزي الخامس
|
|
|