Jessica's teacher has asked her to bring her 0.40 moles of sodium chloride to the laboratory. she should bring approximately grams.

The gene that causes sickle-cell disease is present in a higher percentage of residents of sub-saharan africa than among those of african descent living in the united states. even though this gene causes sickle-cell disease, it also provides some protection from malaria, a serious disease that is widespread in sub-saharan africa but absent in the united states. discuss an evolutionary process that could account for the different percentages of the sickle-cell gene among residents of the two regions.

Why are common names a problem for scientist?

Why does the earth spin slowly, not faster? is it possible to prove it scientifically? can you prove it with math?