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Chemistry, 22.06.2019 03:50
Express the following number in scientific notation. 0.026890 =
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Chemistry, 22.06.2019 10:50
An atom of lithium-7 has an equal number of(1) electrons and neutrons(2) electrons and protons(3) positrons and neutrons(4) positrons and protons
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Chemistry, 22.06.2019 11:40
Modern pennies are composed of zinc coated with copper. a student determines the mass of a penny to be 2.482 g and then makes several scratches in the copper coaling (to expose the underlying zinc). the student puts the scratched penny in hydrochloric acid, where the following reaction occurs between the zinc and the hcl (the copper remains undissolved): zn(s) + 2 hcl(aq) → h2(g) + zncl(aq)the student collects the hydrogen produced over water at 25 °c. the collected gas occupies a volume of 0.899 l at a total pressure of 79 j mmhg. calculate the percent zinc (by mass) in the penny. (assume that all the zn in the penny dissolves.)
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Chemistry, 22.06.2019 16:00
Click the button that shows the correct relationship of the electron affinities of the elements sodium and phosphorus. sodium’s electron affinity value is more negative than the electron affinity value of phosphorus. phosphorus’ electron affinity value is more negative than the electron affinity value of sodium. this information cannot be determined using the periodic table. answer is b on e2020.
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Mathematics, 24.04.2020 23:39
History, 24.04.2020 23:39
Physics, 24.04.2020 23:39
English, 24.04.2020 23:39
Mathematics, 24.04.2020 23:39
History, 24.04.2020 23:39