Why was 1990 an important year regarding air quality?
O The United States took first steps to keep the air clean.
O The United States created the Environmental Protection Agency.
Modifications and improvements were made to the Clean Air Act.
O Funding was established under the Clean Air Act to study air pollution.
Answers: 2
Chemistry, 21.06.2019 15:00
1) how many electrons are in each energy level of the following elements? a. he b. na c. na d. ne 2) how many valence electrons are percent in the following atoms? a. s b. mg c. be d. cl 3) which of the following elements are stable as atoms? a. he b. o c. cl d. ar if you are able to provide the work as to how you got the answers that would be greatly appreciated. : )
Answers: 1
Chemistry, 22.06.2019 00:30
Water (2510 g ) is heated until it just begins to boil. if the water absorbs 5.09×105 j of heat in the process, what was the initial temperature of the water?
Answers: 3
Chemistry, 22.06.2019 18:30
Asample of hydrated tin (ii) chloride (sncl2) has a mass of 4.90 g. when it is dehydrated, it has a mass of 4.10 g. which is the correct chemical formula for the hydrate? sncl2•2h2o sncl2•4h2o sncl2•6h2o
Answers: 2
Why was 1990 an important year regarding air quality?
O The United States took first steps to keep...
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