Decades: 790s 800s 810s 820s 830s - 840s - 850s 860s 870s 880s 890s
Years: 838 839 840 841 842 - 843 - 844 845 846 847 848
Births
Deaths
... selection. This is why materials such as brass, the superconductor YBCO[?], the semiconductor Aluminium gallium arsenide or chocolate are considered mixtures[?] or alloys ...