Photosynthesis

see 13 min Photosynthesis vid by Hank Green for visuals to go with this description... half way along. 

check canva 'photosynthesis' for more on this experiment

FLOATING PHOTOSYNTHESIS

Spinach, plastic cups, dish soap, straw to punch circles of spinach (or hole punch), baking soda, 10ml or bigger syringe. Marking pen.

Backing soda, 300ml water, 1 drop of dish soap, 1/8 tsp baking soda. Stir well avoid bubbles. Punch at least 30 little leaf disks need to be uniform. 10 leaves per syringe. Push plunger back in gently. Suck up several mls of baking soda solution. Allow leaves to float to top, push air out. Put finger over syringe and pull syringe back to create a vacuum. Hold this vacuum for 10-15 secs shaking the syringe slightly. This vacuum removes all the air from air pockets. Remove thumb. Let discs float to bottom. Only proceed once discs have sunk. Put them into a new clear cup. Fill the cup with baking soda solution up to a depth of 3cm. 

REPEAT ABOVE BUT IN WATER, NO BAKING SODA IF YOU WANT TO SHOW DIFFERENT VARIABLES AT WORK. 

Otherwise briefly swirl discs to stop them sticking. Watch for oxygen production. The discs will start to float as photosynthesis makes oxygen bubbles! Very cool!