Answer:
- <u><em>He must use 50g of the 12% solution and 30 g of the 20% solution.</em></u>
<u><em></em></u>
Explanation:
Call x the amount of <em>12% boric acid </em>solution to be used.
- The content of acid of that is: 0.12x
Since he wants to make <em>80 grams</em> of solution, the amount of <em>20% boric acid</em> solution to be used is 80 - x.
- The content of acid of that is{ 0.20(80 - x).
The final solution is <em>15% </em>concentrated.
- The content of boric acid of that is 0.15 × 80 g.
Now you have can write your equation:

Solve:

That is 50 grams of the 12% solution of boric acid.
Calculate the amount of the 20% solution of boric acid:

That is 30 grams.
Then, he must use 50g of the 12% solution and 30 g of the 20% solution.
Photosynthesis is the process by which plants create their food. It involves the operation of enzymes in the plant cells , and they work best at certainpH levels. ... Thus, as the plant's pH drifts away from the best pH, the rate of photosynthesis will decrease.
The answer is E and F.
Hope this helps!!
Talc is not a good choice when building a statue because the mineral Talc is one of the weakest minerals on the Mohs Scale with a hardness of 1 since it could be scratched by a fingernail, which means that when people build a statue with Talc, it could be easily broken down.