What is formed when boiling sulfur reacts with dihydrogen gas?

Four groups are given linking a metal, its ore, and the chemical formula of the main component of the ore. How many of these are correct?
$(1)$ Iron - Magnetite - $Fe_{3}O_{4}$
$(2)$ Iron - Siderite - $FeS_{2}$
$(3)$ Copper - Copper glance - $Cu_{2}S$
$(4)$ Copper - Dolomite - $Al_{2}O_{3}$

Which alloy is used to make surgical instruments?

What are the constituents of solder alloy? Which property of solder makes it suitable for welding electrical wires?

Which of the following metals exist in their native state in nature?
$(i)$ $Cu$
$(ii)$ $Au$
$(iii)$ $Zn$
$(iv)$ $Ag$

Which of the following ores is in the form of carbonate?