Half life is the time taken by a radioactive isotope to decay by half its original mass. In this case, the halflife of the radioactive isotope is 5000 years.
Initially the mass is 100 %; thus the mass that will be left will be given by;
New mass = Original mass × (1/2)^n where n is the number of half lives;
n = 10000/5000 = 2
New mass = 100% ×(1/2)^2
= 100 % × 1/4
= 25%
Therefore; the mass left after 10000 years is 25% or 1/4 of the original mass.
Answer:
D) Adding a catalyst
Explanation:
Adding a catalyst decreases activation energy and allows the reaction to occur more easily.
The most common pH indicator used in Simmons Citrate Agar is Bromthymol Blue (BTB)
Simmons Citrate Agar is a selective and differential medium used for the detection and differentiation of Enterobacteriaceae (gram-negative bacteria).
The medium contains sodium citrate as the sole carbon source, which is used to differentiate organisms based on their ability to utilize citrate as a sole carbon source.
The medium also contains pH indicators that change color based on the pH of the medium. The most common pH indicator used in Simmons Citrate Agar is Bromthymol Blue (BTB).
BTB is a pH indicator that turns yellow in acidic conditions and blue in basic conditions. As the bacteria metabolize the citrate in the medium, they produce acids, which cause the medium to become acidic.
This change in pH is detected by the BTB, which changes color from blue to yellow. The yellow coloration of the medium is an indication that the organism is utilizing citrate as a sole carbon source.
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<span>The Atomic Model was something that was first developed by Neils Bohr. Several years later, Schrodinger took Bohr's basis of a theory and developed it into something larger. So as we can see, theories are a bit like puzzles. When first starting out, one person develops something, or has an idea on something. Others trying to either prove or disprove the original findings, will then test things in a new way, revealing more and more of the puzzle. As the puzzle becomes more and more clear, there is more and more that is revealed. Eventually, we get to a point where we have almost the entire picture, however we are still missing a few key pieces that complete the puzzle. We can see the big picture, but you can not exactly prove out what exactly the details are. This is how scientists such as Bohr and Schrodinger use each others research to build and refine theories. Eventually, we reach a point where we are only missing maybe one or two pieces, and at that point, a theory transitions into almost fact, such as evolution.</span>
