Answer:
fills container, no visible shape, flows
If the Na+ voltage-gated channels in a muscle cell open, the Na (sodium) ions rush inside the muscle cell and makes the cell more positive as Na ions carry positive charge on it. Due to the entry of positively charged ions inside the cell, the cell becomes less negative and more positive. This is called depolarization of cell.
There is also a corresponding diffusion of Chinese and Japanese's forms along this zone
D. electrical to thermal. Hope this helps :)
