BIO Calcium ion synapse transfer Children have about $10^{16}$ synapses that can transfer signals between neurons in the brain and between neurons and muscle cells. Suppose that these synapses simultaneously transmit a signal, sending 1000 calcium ions $\left(\mathrm{Ca}^{2+}\right)$ across the membrane at each synaptic ending. Determine the total electric charge transfer in coulombs during that short time interval. By comparison, a lightning flash involves about 5 $\mathrm{C}$ of charge transfer. (Note: This is a fictional scenario. All human neurons do not simultaneously produce signals.)