Answer:
The charge is +2
Explanation:
Protons are positive, electrons are negative. 10-8=2.
+2 :)
Answer:
The amount of drug left in his body at 7:00 pm is 315.7 mg.
Explanation:
First, we need to find the amount of drug in the body at 90 min by using the exponential decay equation:

Where:
λ: is the decay constant = 
: is the half-life of the drug = 3.5 h
N(t): is the quantity of the drug at time t
N₀: is the initial quantity
After 90 min and before he takes the other 200 mg pill, we have:

Now, at 7:00 pm we have:

Therefore, the amount of drug left in his body at 7:00 pm is 315.7 mg (from an initial amount of 400 mg).
I hope it helps you!
It is false :D I am 95% sure
Answer:
Thermal
Explanation:
When something heats up its atoms become further apart making it melt when something heats up or gets heat or loses heat that's thermal energy