2. electrons exist only at fixed levels of potential energy. however, if an atom absorbs sufficient
energy, a possible result is that

Which of the following elements does soil need in the largest quantities to sustain plant life? a. copper b. iron c. nitrogen d. zinc

Explain how sequences of amino acids in proteins can be used to reveal relationships among organisms.

Will ! a cell containing a 3% sucrose solution is placed into a beaker containing a 7% sucrose solution. assume the cell’s membrane is permeable to water, but not permeable to the sucrose. where will the water diffuse? explain.