We know that metals are the good conductor of electricity .....but when these metals or even non metals combine to form an alloy their properties like Melting point , conductivity also affected

Electrical Conductivity of Alloys

The electrical conductivity of an alloy is generally lower than that of a pure metal due to several factors:

1. Impurities and Alloying Elements: Alloys are composed of a mixture of different elements, including impurities and alloying elements. These additional elements disrupt the regular arrangement of atoms in the lattice structure of the metal, leading to increased scattering of electrons. As a result, the flow of electrons, which is responsible for electrical conductivity, is hindered.

2. Crystal Structure: Alloys often have a different crystal structure compared to pure metals. The addition of alloying elements can cause a change in the crystal structure, leading to a less efficient arrangement of atoms. This alteration affects the movement of electrons, reducing the overall electrical conductivity.

3. Electron Mobility: The presence of impurities and alloying elements in an alloy can decrease the mobility of electrons. These additional elements can create obstacles in the crystal lattice, impeding the movement of electrons through the material. Consequently, the conductivity of the alloy is lower compared to a pure metal with fewer obstacles.

Melting Point of Alloys

The melting point of alloys is generally lower than that of pure metals due to the following reasons:

1. Alloying Elements: The presence of alloying elements in an alloy can significantly affect its melting point. Alloying elements often have different atomic sizes and electronegativities compared to the base metal. This results in the disruption of the regular arrangement of atoms in the lattice structure, making it easier for the metal to transition from solid to liquid state.

2. Solid Solution Formation: Alloys form solid solutions, which are mixtures of two or more elements in the solid state. The formation of solid solutions usually involves the substitution of atoms in the crystal lattice of the metal. This atomic substitution can weaken the metallic bonds, reducing the energy required for the atoms to break free from the lattice and transition into the liquid phase.

3. Interstitial Alloy Formation: Some alloys are formed by the addition of smaller atoms, known as interstitial atoms, into the interstitial spaces of the crystal lattice. This incorporation of interstitial atoms weakens the metallic bonds, making it easier for the alloy to melt at lower temperatures.

Overall, the presence of impurities, alloying elements, changes in crystal structure, and the formation of solid solutions or interstitial alloys contribute to the reduced electrical conductivity and lower melting point of alloys compared to pure metals.