Some of the oldest rocks ever found have been estimated to be about 3.5 billion years old. Is it likely that these rocks were present when Earth was first formed? A. No, this rock is probably just a sedimentary rock that was formed by much younger igneous rocks. B. No, rock material is constantly recycled on Earth as rock is melted into magma. C. No, it is likely that any rocks older than a few hundred years are meteorites from outer space. D. Yes, the oldest rocks on Earth were likely some of the rocks present when Earth was first formed.

Table sugar completely dissolved in water is an example of a?

Count the number of each type of atom in the equation below, and then balance the equation. write in the numbers of atoms and coefficients. add a 1 if there should be no coefficient. cs2(l) + o2(g) → co2(g) + so2(g) c [ ] s [ ] o > c [ ] s [ ] o [ ] cs2(l) + [ ] o2(g) > [ ] co2(g) + [ ] so2(g)

Tooth enamel consists mainly of the mineral calcium hydroxyapatite, ca_10(po_4)_6(oh)_2. trace elements in teeth of archaeological specimens provide anthropologist with clues about diet and diseases of ancient people. students at hamline university measured strontium in enamel from extracted wisdom teeth by atomic absorption spectroscopy. solutions with a constant total volume of 10.0 ml contained 0.726 mg of dissolved tooth enamel plus variable concentrations of added sr. added sr find the concentration of sr in the 10 ml sample solution in parts per billion = ng/ml. find the concentration of sr in tooth enamel in parts per million = mu g/g.