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!
Answer:
Photosynthesis transforms light energy into chemical energy by making sugars. Cellular respiration releases the chemical energy from food by breaking down sugars.
Explanation:
I'm actually learning this in school right now
Hope this helps!
~PurpleMist
Answer:
ns²np⁵
Explanation:
The electronic configuration of elements of halogen group ends with 7 electrons in its outer most shell and they distributed as ns²np⁵.
Such as Cl (17 electron): 2,8,7 which is 1s²2s²2p⁶3s²3p⁵.
Answer:
1) Has a smaller radius than oxygen because of the increased electromagnetic attraction of the nuclei
2) Has a smaller radius than chlorine because all the electrons of F have lower energy levels and have less repulsion of other electrons and hence are more attracted to the nuclei .
Explanation:
Further the electrons are from the nuclei , the bigger the atomic radius is.
(+) attraction of electrons to the nuclei, (-) repulsion of the electrons away from the nuclei.
1) From O to F:
(+) there is one more proton --> Stronger positive charge of the nuclei means that the electrons are attracted more , then they come closer to it and therefore the radius decreases
(-) There is one more electron --> Every electron is repulsed by others away from the nuclei --> the radius increases. But this effect is not so strong because the new electron is added at the same energy level.
Overall the (+) effect is stronger than the (-) effect --> Radius decreases from O to F
2) From F to Cl
(+) there is one more protons --> Same effect as before
(-) There is one more electron --> Every electron is repulsed by others away from the nuclei. But this time the new electrons have a higher energy level --> Meaning that they are less attracted and hence the radius increases.
And also the other inner layers of electrons (electrons of lower energy levels) repulse this new external layer of electrons more effectively than the case of O --> Strong repulsion effect (called electron shielding effect) --> Radius increases
Overall the (-) effect is stronger than the (+) effect --> Radius increases from F to Cl (or decreases from Cl to F)
