Chemistry of Metals and Alloys

A  fuse is the device to protect the electric circuits from over loading and short circuit.
Fuses are safety devices that are to be built into our electrical system. If there were no fuses and we operated too many appliances on a single circuit, the cable carrying the power for that circuit would get extremely hot, short circuit, and possibly start a fire. To prevent electrical overloads, fuses are designed to trip or blow, stopping the flow of current to the overloaded cable.
Fuse is a piece of wire of a material with a very low melting point. When a high current flows through the circuit due to overloading or short circuit, the wires gets heated and melts. As a result, the circuit is broken and current stops flowing. 
Hence, the fuse element is made of zinc, copper, silver, aluminum, or alloys to provide stable and predictable characteristics.
The fuse must always be connected to the mains and it must be of correct value. For example, a 15-ampere fuse should trip when the current through it exceeds 15 amperes. A 20-ampere fuse should blow when the current through it exceeds 20 amps.
Hence, A fuse wire is made of an alloy of lead and tin If the current in a circuit rises too high, the fuse wire melts.

The commonly used fuse wire is made of an alloy of tin and lead.

 Electric fuse wire is a wire which allows only upto a limit of current through it , if a particular amount of value of current is exceeded then it melts down.

Oxides of various metal oxides are converted into metals on heating but CuO (copper oxide) does not not converted into metal on heating but by reaction with Cu2S.

Cinnabar ore is relatively concentrated, it can be processed directly without any intermediate steps to remove waste material and without requirement of a reducing agent. 

 Aluminium being more electropositive than carbon, hence it is not reduced by carbon. Other metal oxides can be reduced by carbon.

Generally carbon is more reactive than $Zn$ and $Cu$. Hence, $ZnO$ and $CuO$ can be reduced by carbon leading to the formation of corresponding metals,  but carbon is less reactive than $Ca$ and $Al$, so $CaO$ and $Al _2O _3$ can not be reduced by carbon .

In catalytic reforming process, high octane number reformate is formed which is the main component of the motor, fuel, aviation gasoline or aromatic rich feedstock. The noble metals platinum and rhenium are the catalysts used on a silica or silica-alumina support base. Fresh catalyst is chlorinated prior to use.

In catalytic reforming process, high octane number reformate is formed which is the main component of a motor, fuel, aviation gasoline or aromatic rich feedstock. The noble metals platinum and rhenium are the catalysts used for it.

Aluminium is the first most abundant metal element and Iron is the next element.

Gold because of its inert nature does not combine with oxygen, hydrogen or humidity easily and thus occur in native state or free state.

Silver and Gold occur in native state (free state). 

The metal found in nature occur in the free or combined state it is generally known as pure metals. A native metal is a metal found in metallic state naturally.  It can be in the pure form or in the form of an alloy.