Chemistry, 06.01.2020 09:31 alexisbarry2398
Ben and jerry were testing powders in science lab. first they put the powder in a zip lock bag. next they added some water. the powder fizzed and bubbled; soon it disappeared. when the bubbling stopped the bag contained a clear liquid and a lot of gas. what is the most obvious sign of a chemical change in this reaction. a) a gas was produced. b) the powder mixed with the water. c) there was a change in temperature. d) the powder dissolved in the water.
Answers: 1
Chemistry, 22.06.2019 12:00
What term is applied to a scientist who studies ancient life, including animal and plant fossils a. anthropologist b. dendroclimatologist c. geophysicist d. paleontologist
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Chemistry, 22.06.2019 17:40
Which statement about hf is true? it is zero for any compound in its standard state. it is positive when the bonds of the product store more energy than those of the reactants. it is negative when a compound forms from elements in their standard states. it is zero for any element that is in the liquid state.
Answers: 1
Chemistry, 22.06.2019 21:40
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.
Answers: 2
Ben and jerry were testing powders in science lab. first they put the powder in a zip lock bag. next...
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