Chemistry, 03.07.2019 14:30 skyemichellec
Asample taken from a layer of mica in a canyon has 2.10 grams of potassium-40. a test reveals it to be 2.6 billion years old. how much potassium-40 was in the sample originally if the half-life of potassium-40 is 1.3 billion years? a. 4.20 g b. 8.40 g c. 12.6 g d. 16.8 g e. 25.2 g
Answers: 1
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This drawing shows a human body system. what is the primary function of this body system?
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The blackbody curve for a star name zeta is shown below. what is the peak wavelength for this star ?
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Chemistry, 22.06.2019 08:30
Sally is making a model of a magnesium atom with an atomic mass number of 24 for her chemistry class. she has foam balls for the protons, neutrons, and electrons. she has added 6 neutrons to her model so far. how many more neutrons does she need to add to complete her neutral atom of magnesium?
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Chemistry, 22.06.2019 20:00
There are two steps in the usual industrial preparation of acrylic acid, the immediate precursor of several useful plastics. in the first step, calcium carbide and water react to form acetylene and calcium hydroxide: cac2 (s) + 2h2o (g) → c2h2 (g) + caoh2 (s) =δh−414.kj in the second step, acetylene, carbon dioxide and water react to form acrylic acid: 6c2h2 (g) + 3co2 (g) + 4h2o (g) → 5ch2chco2h (g) =δh132.kj calculate the net change in enthalpy for the formation of one mole of acrylic acid from calcium carbide, water and carbon dioxide from these reactions. round your answer to the nearest kj .
Answers: 3
Asample taken from a layer of mica in a canyon has 2.10 grams of potassium-40. a test reveals it to...
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