Answer:p waves hope that helps
1. First taking in light, then electron transport
2. A main fuel for your brain. Without it, your brain wouldn't function well. Yes, you need it.
The third equation is properly balanced.
To figure this out, set up tables to check if each element has the same amount on both sides. If you do this for the third equation, copper, hydrogen, oxygen, and nitrogen are all balanced,
The first equation is incorrect due to the fact Iron, Fe, is not balanced on both sides. This is shown by the subscripts given.
The second equation is incorrect as Sulfur is not properly balanced and neither is sodium.
The fourth equation is incorrect as Aluminum is not properly balanced. On the reactants side, Aluminum is 4 while on the products, Aluminum is 8.
Hope this helps!
B. Endorphins are released during exercise
Answer: norfenefrine 
Explanation:
Depression in freezing point is given by:
= Depression in freezing point
i= vant hoff factor = 1 (for non electrolyte)
= freezing point constant = 
m= molality
Weight of solvent (ethanol)= 
Molar mass of unknown non electrolyte = M g/mol
Mass of unknown non electrolyte added = 82 mg = 0.082 g (1g=1000mg)
The molecular mass of norfenefrine is near to 154 and thus the identity of the white powder is norfenefrine .
