Write a description of how you know a chemical reaction is occurring.

there are certain changes that signify that a chemical reaction has taken place or no.

Change in colour

Change in state

Change in temperature

Evolution of gas ,etc.

hope that helps ✌

dopamine..

"it was found that some people who were taking the drug l-dopa to raise their levels of dopamine were developing schizophrenic-like symptoms supporting research a strength of the dopamine hypothesis is that there are many studies which have shown support for the neurochemical explanation."

the answer is f1 and d2 because if you put equal force on those two points the beam would balance trust me on this