D has the fastest reaction rate because dynamite explodes almost immediately.
A isn't correct because rusting nails take forever to completely rust.
B isn't correct because logs burning can take around 10 to 20 minutes.
C isn't correct because food digestions takes anywhere between 10 minutes to an hour.
Density can be defined in terms of the mass of a substance present in a certain volume.
i.e. Density = Mass/ volume
It helps classify and identify matter due to the following reasons:
1) Density is an intensive property. For a given substance the density will remain the same irrespective of the amount in which it is present.
For example: The density of Aluminum (Al) = 2.7 g/cm3. This value is a constant at a certain temperature and pressure. Therefore, the density will remain the same for 1 kilogram or 1 mg of Al
2) Different elements/compounds have different values of densities which is characteristic of that substance
L is amplitude M is wavelength and P is frequency
Robert Boyle, the 17th century British chemist, first noticed that the volume of a given amount of gas is inversely proportional to its pressure when kept at a constant temperature. When working with ideal gases we use PV = nRT, but remember n, R, and T are all constant. Therefore we have:
PV(before) = PV(after)
P(0.5650) = (715.1)(1.204)