When a solid forms with two solutions are mixed it is a precipitate
<u>Answer:</u>
<em>Silver tarnishing as the silver metal reacts with sulphur is a chemical change.</em>
<u>Explanation:</u>
Tarnishing is the process of chemical change occurring on the surface of objects leading to corrosion or other defects on the surface. The remaining options like dilution, eroding is a physical change where the concentration of salt and rock particles will be decreased, respectively.
Similarly for soil drying also the concentration of water will be decreased leading to a physical change from wetty or dry soil.
But the last option which indicates tarnishing of silver metal on reaction with sulphur is a chemical process as the surface of silver metal will be reacting to sulphur and leads to lose of electrons which leads to corrosion of the surface or tarnishing of silver.
Inertia depends on the mass of an object.
Answer : The temperature in degree Celsius is, 
Explanation :
The conversion used for the temperature from Kelvin to degree Celsius is:

where,
= temperature in Kelvin
= temperature in centigrade
As we are given the temperature in Kelvin is, 2.7
Now we have to determine the temperature in Kelvin.



Therefore, the temperature in degree Celsius is, 