PLEASE Help WILL MARK BRAINILIST Chemical energy sources are often portable and provide large amounts of energy. Fossil fuels are one kind of chemical energy source. Most of the energy we use in the United States is generated by the combustion of fossil fuels. However, fossil fuel combustion adds greenhouse gases to the atmosphere, mostly CO2. One measure of the total amount of greenhouse gases that are emitted into the atmosphere each year is called a carbon footprint. Study these images to compare the carbon footprint of an average person in the United States to an average person around the world.

Knowing that greenhouse gases are contributing to climate change, how can we reduce our carbon footprint, particularly in the United States? Could hydrogen fuel replace fossil fuels in the future? Why or why not? Should the size of a person’s carbon footprint be limited by law? Why or why not?

Nanotechnology, the field of trying to build ultrasmall structures one atom at a time, has progressed in recent years. one potential application of nanotechnology is the construction of artificial cells. the simplest cells would probably mimic red blood cells, the body's oxygen transporters. for example, nanocontainers, perhaps constructed of carbon, could be pumped full of oxygen and injected into a person's bloodstream. if the person needed additional oxygen-due to a heart attack perhaps, or for the purpose of space travel-these containers could slowly release oxygen into the blood, allowing tissues that would otherwise die to remain alive. suppose that the nanocontainers were cubic and had an edge length of 24 nanometers. part a part complete what is the volume of one nanocontainer? (ignore the thickness of the nanocontainer's wall.) express your answer using two significant figures. v v = 1.4ă—10â’20 l previous answers correct significant figures feedback: your answer 1.3824â‹…10â’20 = 1.382ă—10â’20 l was either rounded differently or used a different number of significant figures than required for this part. if you need this result for any later calculation in this item, keep all the digits and round as the final step before submitting your answer. part b suppose that each nanocontainer could contain pure oxygen pressurized to a density of 81 g/l . how many grams of oxygen could be contained by each nanocontainer?