The tea was no longer hot or (brewed) so the 5th didn’t dissolve like the others because the tea was hot or warm enough anymore it cooled down. So the sugar won’t dissolve no more.
Hi, you've asked an incomplete question. However, I assumed you are referring to the article found on the Scientific American website.
Explanation:
<em>Remember,</em> according to that article we are told that scientists notice that these insects have a long nymphal (immature form before becoming adults) stage, one that can last up to 13 to 17 years on the ground before they leave the ground looking for mating partners.
Because it is only after mating occurs at this point that their eggs are laid, that is why scientists believe that cicadas only reproduce every 13 or 17 years.
Answer:
1x10^-8 M
Explanation:
Since the solution turns blue, it mean the solution is a base.
Now, to know which option is correct, we need to determine the pH of each solution. This is illustrated below:
1. Concentration of Hydrogen ion, [H+] = 1x10^-2 M
pH =..?
pH = - log [H+]
pH = - log 1x10^-2
pH = 2
2. Concentration of Hydrogen ion, [H+] = 5x10-2 M
pH =..?
pH = - log [H+]
pH = - log 5x10^-2
pH = 1.3
3. Concentration of Hydrogen ion, [H+] = 5x10 M
pH =..?
pH = - log [H+]
pH = - log 5x10
pH = - 1.7
4. Concentration of Hydrogen ion, [H+] = 1x10-8 M
pH =..?
pH = - log [H+]
pH = - log 1x10^-8
pH = 8
A pH reading shows if the solution is acidic or basic. A pH reading between 0 and 6 indicates an acidic solution, a pH reading of 7 indicates a neutral solution while a pH reading between 8 and 14 indicates a basic solution.
From the above calculations, the pH reading indicates a basic solution when the hydrogen ion concentration was 1x10^-8 M.
C. pain reliever
ex. tylenol, aleve, etc.
Equation for Half life :
A = a(0.5)^(t/h)
A is current amount, "a" is initial amount, h is halflife, t is time
5 = 40(0.5)^(t/1.3x10^9)
5/40 = (0.5)^(t/1.3x10^9)
take the log of both sides , power rule
Log(5/40) = (t/1.3x10^9) * Log(0.5)
(1.3x10^9) * Log(5/40) / Log(0.5) = t
3.9x10^9 years = t
And if you think about what a half life is, the time it take for the amount to reduce to half.
40/2 = 20
20/2 = 10
10/2 = 5
It went through 3 half-lifes
3 * 1.3x10^9 = 3.9x10^9 years
