The reactivity of an atom is due to the number and arrangement of in the outer energy level.

a. protons
b. electrons
c. neutrons

Secondary pollutants are more harmful than primary pollutants. select the best answer from the choices provided ot of

Two students are working together on an experiment that measures the effect of different liquid fertilizers on the thickness of plants’ stems. which is most likely to result in the greatest amount of error in their scientific experiment? a. one student measures the plant stem widths by using calipers. the other student measures the widths of the same plant stems again by using a different pair of calipers. b. one student measures the plant stem widths by using calipers. the other student types the measurements as they are taken into a computer spreadsheet. c. one student weighs liquids for the experiment by using a calibrated scale. the other student weighs liquids for the experiment by using a different calibrated scale.

What is the next step in the process after a substrate enters the active site of an enzyme