Organic molecule. In particular, a carbohydrate.
<span>Magnesium is a strong anode than calcium. So, Mg will be oxidized into Mg2+. So instead of having Ca being the reducing agent, Mg will takes its place. That's how the "Blocking" occur.
</span><span>Without Ca2+, no neurotransmitter was released because the exocytosis of the synaptic vesicles is dependent upon Ca2+.
</span>So, when magnesium is added to the extracellular fluid it blocks the calcium channels and inhibits the release of <span>neurotransmitter.</span>
It is physical change because ? has changed alone not with chemicals
