Archaeological Chemistry

Answer the following questions, showing calculations and equations where appropriate: 1. You're working with pottery that is tempered with an extremely pure quartz sand (quartz is silica, SiO2). Assuming that the clay component in your sherds is about 15% silicon (Si), and the sherds themselves assay out to about 30% silicon, calculate the effect of the sand temper on the other elements you're measuring in the sherds. How would you correct for this effect if you wanted to compare your sherd compositions to raw (untempered) clay compositions?

Archaeological Chemistry

Answer the following questions, showing calculations and equations where appropriate: 1.Steponaitis, Blackman, and Neff (American Antiquity 61:555-572, 1996) use the following correction for bulk elemental concentrations measured in shell- tempered pottery: e' = (1000000*e)/(1000000-2.5Ca), where e' = corrected elemental concentration, e = originally measured elemental concentration, Ca = concentration of calcium, and all measurements are in parts per million (ppm). Explain how this correction works. Hint: Assume that the shell temper is pure calcium carbonate, CaCO3.

Archaeological Chemistry

Answer the following questions, showing calculations and equations where appropriate: 1. Zircon grains are extremely resistant to chemical weathering and thus they tend to be ground down mechanically into very fine sand and silt particles. In light of this observation, what element(s) would you expect to see enriched in ceramics made from silty clays?

Archaeological Chemistry

Answer the following questions, showing calculations and equations where appropriate: 1. You have a radiocarbon sample analyzed and find out that the sample has 60% of the modern level of radiocarbon. Calculate the radiocarbon age of the sample using (a) an assumed 5730-year half-life and (b) a 5568-year half-life.

finding expressions for the partial molar volumes at T and P

The molar volume (cm^3 mol^-1) of a binary liquid mixture at T and P is given by: V = 120x1 + 70x2 + (15x1 + 8x2)x1x2 (a) Find expressions for the partial molar volumes of species 1 and 2 at T and P. (e)Plot values of V, partial V1, and partial V2 calculated by the given equation for V and by the equations developed in (a) vs. x1. Label points V1, V2, partial V1 infinity, partial V2 infinity, and show their values. I don't know where to start on this. The instructor says that this is a Redlich-Kiester expansion where they've fit an excess molar volume? Like, 120 is the pure molar volume for x1 and 70 is the pure molar volume for x2. The partial V1 infinity and partial V2 infinity means ... click for more