Answer:
Historically, wood was the main source of U.S. energy until the mid-1800s and was the only commercial-scale renewable source of energy in the United States until the first hydropower plants began producing electricity in the 1880s.
The Advantages of Renewable Energy Resources-A Fuel Supply That Never Runs Out.Zero Carbon Emissions.Cleaner Air and Water.Disadvantages of Renewable Energy-he Electricity Generation Capacity is Still Not Large Enough.Renewable Energy Can be Unreliable.
First, we need to take advantage of the world's abundant natural gas resources and reduce coal consumption;
Second, governments must support development of carbon capture and storage technology to make fossil fuel use cleaner;
Explanation:
<u>a) Answer: </u>
<em>Number of molecules in 1 mole</em>
<u>Explanation:</u>
a) Whether we take any of the substance among all three of the given substances they will have the same number of molecules in 1 mole of the substance is considered and the value for this will be 
<u>b) Answer: </u>
<em>In the given question </em><em>mass of the substance</em><em> which is </em><em>greatest</em><em> is asked for </em><em>one mole</em><em> and we also know that </em><em>mass of one mole is given by molar mass. </em>
<u>Explanation:</u>
b) It is known that 
is the molar mass for oxygen which is greater than that of hydrogen while fluorine has a molar mass of 
which on comparison shows that, it is the highest amongst all three.
Answer:Strontium-90 and cesium-137 have half-lives of about 30 years (half the radioactivity will decay in 30 years). Plutonium-239 has a half-life of 24,000 years. High-level wastes are hazardous because they produce fatal radiation doses during short periods of direct exposure.
Explanation:
Answer:
francium, caesium, helium
