An action potential is

according to google

"An action potential is part of the process that occurs during the firing of a neuron. During the action potential, part of the neural membrane opens to allow positively charged ions inside the cell and negatively charged ions out. This process causes a rapid increase in the positive charge of the nerve fiber."

go to settings and press notifications find the brain oh app and turn the switch so it would turn greyish silver color

pattern wax

explanation:

pattern wax is used for casting restoration as part of lost-wax technique.