Chemical properties of metals

Occurrence of metals

The occurrence of metals varies depending on their reactivity. The more reactive metals are typically found as compounds in nature, while less reactive metals are found as free, uncombined elements.

Metals in order of reactivity and their natural forms

Metal	Main Form in Nature
Potassium	Potassium chloride
Sodium	Sodium chloride
Calcium	Calcium carbonate (limestone/chalk)
Aluminum	Aluminum oxide
Zinc	Zinc sulphide
Iron	Iron oxide or iron sulphide
Tin	Tin oxide
Lead	Lead sulphide
Copper	Copper pyrites (CuFeS₂)
Mercury	Mercury sulphide
Silver	Silver sulphide
Gold	Occurs as a free element
Platinum	Occurs as a free element

Location of metals in Tanzania

Most metals in Tanzania are found naturally as minerals. These minerals are extracted from ores, which are rocks containing enough metal compounds for the extraction of metals. Common ores include oxides, such as haematite, which contains iron (III) oxide. Other ores contain metal compounds like copper (II) carbonate found in malachite.

Notable mineral deposits in Tanzania include:

• Gold: Found in Geita (Mwanza), Kahama (Shinyanga), Nyamongo, Buhemba, Majimoto (Mara), and Nzega (Tabora).
• Iron: Haematite ore found in Liganga (Iringa).
• Copper: Found in Mpanda (Rukwa) and Morogoro.
• Sodium: Found in the form of sodium chloride in Uvinza (Kigoma), soda ash (Na₂CO₃) in Lake Natron, rock salt in Kilwa, and dissolved salt (NaCl) in seawater.

Other metals found in Tanzania

Metal/Mineral	Location
Copper	Mpanda (Rukwa), Morogoro
Tin	Misemyi (Kagera)
Phosphate	Minyingu (Lake Natron, Manyara)
Uranium	Namtumbo (Ruvuma)
Iron (Haematite Ore)	Liganga (Iringa)
Gold	Geita (Mwanza), Kahama (Shinyanga), Nyamongo, Buhemba, Majimoto (Mara), and Nzega (Tabora)