Chemistry, 09.04.2020 02:51, hansen8031
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Radioactive elements decay at a know rate known as half-life. Choose all of the correct statements concerning half-life.
Carbon-14 has a half-life of 5,730 years. A 30 gram sample will be 10 grams after 5,730 years.
Nickel-59 has a half-life of 76,000 years. A sample would go through 3 half-lives in 228,000 years.
Hafnium-182 has a half-life of 9 million years. A 38 gram sample would be 4.75 grams in 27 million years.
Iron-60 has a half-life of 1.5 million years. In 6 million years a 40 gram sample would be reduced to 10 grams.
Lead-202 has a half-life of 52,500 years. The original sample must have been 120 grams if you have a 60 gram sample after 105,000 years.
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Chemistry, 22.06.2019 05:30, smartie80
Transportation is the largest single source of air pollution in the united states. air pollution can harm the environment and human health. which technology could offer a solution to this problem? mufflers that reduce noise motors that run on electricity tires that improve gas mileage
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Chemistry, 23.06.2019 10:10, estebanmff
Solid tin exists in two forms: white and gray. for the transformation sn(s, white) ā sn(s, gray) the enthalpy change is -2.1 kj/mol and the entropy change is -7.4 j/(mol*k). a. calculate the gibbs free energy change for the conversion of 1.00 mol white tin to gray tin at -30ā. b. will white tin convert spontaneously to gray tin at -30ā? c. at what temperature are white and gray tin thermodynamically equivalent at a pressure of 1 atm?
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Chemistry, 23.06.2019 10:30, malum2009
Can anyone explain 1. review your spectrometry data and use the known elements to identify the star's composition. which unknown elements make up this star? justify your element selections. 2. in parts i and ii of the lab, what happened to the electrons of each element to produce the different colors of light? explain your answers using important terms from the lesson and information provided in the laboratory. 3. stars composed of heavier (more massive) elements are often slightly older than stars made predominantly from hydrogen and helium. based on your data, is the newly discovered star a younger star? explain your answer.
Answers: 2
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