The answer is mercury. Mercury is a liquid metal, while the others are all solid metals. Mercury is also the only metal that is liquid at room temperature. It is a very dense metal, and it is also a very good conductor of electricity. Mercury is used in a variety of applications, including thermometers, barometers, and switches. It is also used in some dental fillings. However, mercury is also a very toxic metal, and it can be harmful to human health if it is inhaled or ingested.
Aluminium is a silvery-white metal that is lightweight and strong. It is the most abundant metal in the Earth’s crust, and it is used in a variety of applications, including construction, packaging, and electronics.
Copper is a reddish-brown metal that is ductile and malleable. It is a good conductor of heat and electricity, and it is used in a variety of applications, including electrical wiring, plumbing, and coins.
Iron is a grayish-white metal that is strong and hard. It is a good conductor of heat and electricity, and it is used in a variety of applications, including construction, machinery, and tools.
Zinc is a bluish-white metal that is hard and brittle. It is a good conductor of electricity, and it is used in a variety of applications, including batteries, galvanizing, and alloys.