The half life equation is -->P(t) = Pi (0.5) ^ (t/c)
c is equal to the element to reach its half-life (5 seconds)t is equal to the duration of time the element is expose to (20 seconds)Pi is the initial amount (340)0.5 is the base of this exponential function to represent half-life.P(t) is the expression for the function of time
P(20) = 340 (0.5)^20/5P(20) = 340 (0.5) ^4P(20)= 21.25 grams
Fraction = P(t)/Pi = P(20)/Pi =21.25/340 =1/16
Therefore, when given 20 seconds, 340 grams of Fluorine-21 will degrade to 21.25 grams OR 1/16 of its original mass.
Hope this method helps! (This is my answer btw, I think you may have accidentally posted twice?)
My thought would be B) gases.
I could be wrong but that's what i'd say
Hi!
The generic equation showing how a weak base ionizes water is the following:
B(aq) + H₂O(l) ⇄ BH⁺(aq) + OH⁻(aq)
A base is described as weak when its dissociation is difficult and isn't complete. Weak Bases are chemical compounds that accept protons from water, to form the conjugate acid and the OH⁻ ion. The pH of the solution of a weak base is higher than 7. Some weak bases include ammonia (NH₃), Aluminum Hydroxide (Al(OH)₃) and Sodium Acetate (CH₃COONa).
Have a nice day!
Increase the force they are using to move the box by adding more helpers
Explanation:
If you want to increase the speed that the box is moving, increasing the friction would make it more difficult, decreasing the force they are using would just make it slower and increasing the angle of the ramp would make it harder. Adding more people would make it easier. “The more the merrier”
A: incorrect because there will be no effect on keeping the rats in separate cage in the same room at the time of the experiment.
C: incorrect because it's depend upon scientist whether he wants to record the observation on the graph or on the table. Thus, no affect will be caused on the observations.
D: incorrect because peer review is done only after the experiment is completed.
Thus, statement B is correct because the growth graph of male and female of any species is different. Male tend to grow more than their female counterparts. So, for the process of the study it is essential that all the rats included are either male or female.
Hence, option (B) is correct.
