Chemical weathering is the process by which rocks are broken down by chemical reactions. There are different types of chemical weathering. Hydrolysis is the chemical breakdown of a substance when combined with water. The most common example of hydrolysis is feldspar in granite rocks changing to clay.
Racially Africans originated in Africa, Europeans in Europe and so on. (before that the human species originated in Africa, but that's ancient history) African Americans are an ethnic group, or a subrace of the African race.
African Australians are Australians of African ancestry. Large-scale immigration from Africa to Australia is only a recent phenomenon, with Europe and Asia traditionally being the largest sources of migration to Australia.ore than 70 per cent of those from West African countries remained in Australia following military coup d'etats Ã©tats in their countries of. Birth, ultimately, however immigration From africa To australia generally remained limited until the. 1990s