there are 7 electrons in bromines valence level
Answer:
6CO2 + 6H2O → C6H12O6 + 6O2 = A+B--->C+D
During Stage A the muscles and tendons are working in unison to pull the leg backward and upward. In Stage B the tendons are being stretched and the muscles in the leg are driving forward, releasing their pent up energy (the muscles will burn oxygen until they run out at which point they will start producing lactic acid to keep providing energy for the leg, which is why your muscles burn when they are tired)
A selectively permeable membrane allows materials (some substances or molecules) needed for survival in and out. (Like a filter)