The table shows the amount of radioactive element remaining in a sample over a period of time. Radioactive Decay Rate
Amount of Radioactive Sample Time
(grams)
(hours)
186.0
0
147.0
7
117.0
14
93.0
21
23.3
63
Part 1: What is the half-life of the element? Explain how you determined this.
Part 2: How long would it take 320 g of the sample to decay to 2.5 grams? Show your work or explain your answer.

Consider the directing effects of the substituents on salicylamide and predict the possible structures of the iodination products. which do you think will be the major product?

How many moles of sulfur dioxide are produced when 4.38 moles of oxygen completely react with iron (iv) sulfide

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.