Chemistry, 30.01.2020 05:56 josuemarquezz27
Which statement best compares coal and ores?
both are burned for energy.
both take millions of years to form.
both require oxygen to form.
both are used to make coins.
Answers: 3
Chemistry, 22.06.2019 09:30
The chart shows the bid provided by four contractors to complete a job. which contractor is the most cost-effective?
Answers: 3
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.)
Answers: 1
Chemistry, 23.06.2019 00:00
If many scientists conduct the same or similar experiments, and all obtain similar results, a can be written, which is a generally agreed-upon statement that explains and predicts how a natural phenomenon works.
Answers: 1
Which statement best compares coal and ores?
both are burned for energy.
both take mi...
both are burned for energy.
both take mi...
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