Answer: I think, the number of oscillations in a given period of time.
Explanation: Well I guess because in a period time is known as the rate of occurrence of the wave. Hope this helps!
Seismic wave is the answer
That is because it is impossible to create a law for the behavior of every single different gas, so creating laws for an ideal gas helps us understand the basic nature of gasses which might or might not differ slightly or a lot. By understanding how an ideal gas works, we can understand how a normal gas works.
Since there is no decimal point in the number given above, the counting for the number of the significant figures will start from the left. Then, the first zero from the left is insignificant. Therefore, in this number there are 6 significant figures.