Answer:
600 mg
Explanation:
The initial amount of the drug = 200 mg
The half-life of the drug = 8 hrs
It means that:-
After 6 hours, the concentration becomes :-
mg
After 12 hours, the concentration becomes :-
mg
After 18 hours, the concentration becomes :-
mg
And so on...
Thus,
After infinite time = 
Thus,
After infinite time = 
The sum of the infinite series is:-
= 
So,
<u>After infinite time =
mg = 600 mg</u>
Let us calculate the structure of the electric shells of the Al atom. It has an atomic number of 13, so it has 13 electrons. The first 2 go to the first hell. The next 8 need to go to the second shell and the last 3 ones would go to the outermost shell. The outer shell, that is the most important one for chemical reactions, has thus 3 electrons. An atom always tries to have a completed outer shell (with either 2 or 8 atoms). It is easier for a cell to have a charge of +3 than a charge of -5 (smaller absolute value) and thus the Aluminum atom will try to get rid of the 3 electrons. In this process, it loses negative charge thus it will become positively charged. Hence, the correct answer is that it will prefer to lose 3 electrons and become positively charged.
Answer:
0.053moles
Explanation:
Hello,
To calculate the number of moles of gas remaining in his after he exhale, we'll have to use Avogadro's law which states that the volume of a given mass of gas is directly proportional to its number of moles provided that temperature and pressure are kept constant. Mathematically,
V = kN, k = V / N
V1 / N1 = V2 / N2= V3 / N3 = Vx / Nx
V1 = 1.7L
N1 = 0.070mol
V2 = 1.3L
N2 = ?
From the above equation,
V1 / N1 = V2 / N2
Make N2 the subject of formula
N2 = (N1 × V2) / V1
N2 = (0.07 × 1.3) / 1.7
N2 = 0.053mol
The number of moles of gas in his lungs when he exhale is 0.053 moles
the time it take for a planet to rotate on its axis makes up its day so if it were slower the day would be longer like earth, it take about 24 hours to make one full rotation.
Now for a year the distance from its star is the largest factor, because the further out the longer it takes to revolve around it, thus making a longer year.