How long will a golf ball stay in the air after being dropped?

This aquarium exhibits biotic and abiotic factors in an aquatic environment. one of the abiotic factors is

What initially causes a nerve impulse? release of enzymes out of the neuron movement of chemicals into the dendrites of the neuron pathogens attacking the dendrites of the neuron red blood cells bathing the neuron

If you have a difficult time knowing where your hand is without looking at it you may be having a problem with your what ?