Mercury, also called quicksilver, is the only metal that is liquid at room temperature. Mercury is a heavy metal and is very toxic.
Mercury is used to dissolve gold in the process of gold mining, it was used in making felt, in older style thermometers, and in dental fillings.
Pewter is a metal alloy made from around 85% tin, and the remainder being antimony, about 1% copper and 4 or more percent lead. It is commonly used for photo frames, vases and decorative mugs. Plates, bowls and cups were all made from pewter before glass and porcelain became more common.
People of ancient cultures used to get lead poisoning partly from eating from pewter plates, and partly from using a lead compound to sweeten their wine.
Silver is a soft, shiny metal that can be polished to be highly reflective. It tarnishes easily, however. Silver is very conductive and today is used electrical components. Silver is widely used for making jewellery, and was used for making tableware like knives and fork. As pure silver is so soft, most practical items made from silver are made from an alloy of silver and another metal like copper.
Steel is an alloy of iron and small amounts of carbon, chrome and other metals. Steel is much, much harder than iron and is much more useful for making things out of.
Steel is used heavily in building construction, making land and sea vehicles of all kinds, and many household appliances. Some types of steel can still rust, but surgical and stainless steel are far less prone to rusting.
Something made from metal is tarnished if it has a layer of a dull, colored substance on it instead of being bright, shiny and reflective.
Tarnish is a different color on different kinds of metal. silver tarnish is black and copper tarnish is green. Some metals do not tarnish, instead they rust, which can eat away all of the metal over time instead of just leaving a thin coating on the surface.