Hello everyone... I am in a university-level science coarse and I am having real trouble with this question on our HW assignment as I am not a math oriented individual.... Any help is greatly appreciated. I know its long, but I am really terrible at this whole math thing.

Thanks again..

Their starting point was the assumption that the total mass or iridium in the K/T

layer was equal to the mass of iridium in the original impactor:

m

Ir(layer) = mIr(impactor)

1) First you must estimate the mass of iridium in the K/T layer. Use the following

information:

a. On average, the iridium layer is

*H *= 3 cm thick (what is it in SI units?).

b. The density of the K/T layer containing iridium is *d *= 2.5 g/cm3 (what is it in SI

units?).

c. On average, the layer had a concentration of iridium of *CIr(layer) *=20 parts per

billion (20 ppb) by weight. (*Hint*: in scientific notation, 1 billion is 109, so 1 ppb is

equivalent to 1/109 or 10-9)

d. Assume that the iridium concentration was uniform around the Earth.

e. The total area of the Earth is *AEarth *= 4 π×(REarth)2

where the radius of Earth is

*REarth *= 6378 km (what is it in SI units?).

f. The total mass of the K/T layer, *m(layer)*, is given by the area of the Earth (AEarth)

multiplied by the layer thickness (*H*) multiplied by the layer density (*d*).

g. The total mass of iridium in the K/T layer is given by the mass of the layer

multiplied by the iridium concentration:

m

Ir(layer) = m(layer)×CIr(layer)