Asample of sodium bicarbonate is known to contain some impurities. it is found that na makes up 18.00% of the entire mass of the sample. all of the na comes from the nahco3 compound. find the mass percent of nahco3 in the sample

The diagram shows the structures of horse and cat forelimbs. what does the diagram suggest about the evolutionary relationship between these two mammals? a. they have homologous structures, indicating a common ancestor. b. they have analogous structures, indicating a common ancestor. c. they have homologous structures, indicating that they do not have a common ancestor. d. they have analogous structures, indicating that they do not have a common ancestor.

When you mate two plants together the terms is called? answer it fast as possible plz! i have a test tomorrow!

What must occur for air masses to form fronts