Scientists search for fossil fuels in many ways. sending a sound wave into the ground (by exploding dynamite, thumping the ground with a large weight, or using an electric vibrating machine) and measuring its return to the surface at receiving stations is called surveying.

seismic

Explanation:

Seismic surveying is a kind of geophysical surveying in which the properties of the Earth are measure by using the physical principles and parameters like the magnetic, gravitational, thermal, electrical and elastic theories.

It is the measure of the response of various parameters to the elastic disturbances which is known as seismic waves.

The reaction of the fossil fuel to such waves helps to determine their existence.

the density of gold = 19.3 g/cm3

the relation between density and mass and volume is

density = mass / volume

given :

mass of gold = 13 g

density = 13g / volume = 19.3

volume = 13 /19.3 = 0.67 cm^3

thus volume of gold nugget = 0.67 cm^3